The Lazarus Experiment

The Doctor returns Martha to her flat, twelve hours relative to after she first stepped in the TARDIS. Clued in by a telephone call by Martha's mother Francine that her sister Tish is on the television, they watch a news report with a statement from the elder Professor Richard Lazarus, announcing that later that night, with one demonstration, he will "change what it means to be human". The Doctor leaves in the TARDIS, but quickly rematerialises when he recognises the impact of Lazarus' statement. They dress for the formal dinner party at Lazarus Labs, and meet up with Tish, who works for Lazarus; Francine, Martha's mother; and Leo, Martha's brother; Francine is immediately suspicious of the Doctor's interest in Martha. Their conversation is interrupted as Lazarus announced he will perform a miracle and steps into a capsule in the center of the reception room. Technicians start the machine, filling the capsule with strange energy, and the Doctor quickly steps in when he believes that the system is overloading. As the machine comes to a stop, Lazarus leaves the capsule, now a much younger man; his machine is able to manipulate the subject's DNA to make them younger. The Doctor, highly concerned of unknown side effects, is able to gain a sample of Lazarus' new DNA when Lazarus kisses Martha's hand, and, with Martha's help, discover that the DNA is unstable.
As they investigate, Lazarus returns to his office along with his partner, the elder Lady Thaw. She insists that she be the next to undergo the process so they can be young together, but he refuses as he didn't want to "waste another life with you [her]". As she threatens to have Mr. Saxon pull their funding, Lazarus begins to undergo a transformation into a scorpion-like being, and kills Lady Thaw by draining her life energy, leaving her a zombie-like corpse; after returning to his human form, Lazarus returns to the reception, while the Doctor and Martha shortly find Thaw's body, the Doctor surmising that Lazarus must drain the life energy to keep his DNA stable. The Doctor and Martha, along with Tish, quickly return to the reception area and warn everyone to escape as Lazarus transforms again. The Doctor lures Lazarus away as Martha and Tish use the sonic screwdriver to override the building's security lockdown and saving the remaining guests. Martha rejoins the Doctor and the two take shelter in Lazarus' device, the Doctor believing he will not harm his own invention. The Doctor also explains that Lazarus's transformation is the result of an evolutionary throwback locked away in dormant human genes that are now becoming dominant. Unfortunately, Lazarus manages to activate his device, but the Doctor reverses the polarity, causing the field to affect only Lazarus outside of the capsule. They emerge to find Lazarus in his human form naked and apparently dead.
As the police and medical workers arrive to take care of the wounded, Lazarus' body is taken by an ambulance. However, when the Doctor hears a nearby crash, he, Martha, and Tish race to discover the ambulance has crashed, its drivers drained of life. They find that Lazarus, alive but human, has taken shelter in Southwark Cathedral. The Doctor tries to reason with Lazarus but is unable to stop him transforming again. Martha and Tish, under the Doctor's orders, lure the creature to the top of the Cathedral's bell tower, while the Doctor manipulates the church's pipe organ to produce the maximum volume it can. The vibrations caused by the organ interfere with Lazarus' manipulated DNA, and he falls to his death to the floor below, transforming one last time to his human form.
Martha and the Doctor return to her flat, and the Doctor offers Martha on board, more than just as a passenger, which she accepts. As the TARDIS dematerialises from the flat, Martha's voice mail records Francine's warning to her daughter about the dangers of the Doctor as told to her by Mr. Saxon.

Evolution of the Daleks

After the creation of the hybrid Human-Dalek Sec, The Doctor, Martha, Frank, Laszlo, and the other human captives manage to escape when the Doctor uses his sonic screwdriver to cause a nearby radio to emit a high-pitched frequency. Daleks Jast and Caan give chase, but confer amongst themselves concern over Sec's plan. The Doctor and Martha meet up later with Tallulah, Laszlo and Frank, and make their way back to Hooverville. The Doctor warns Solomon about the Daleks and they are seeking out more human subjects, but Solomon believes he can reason with them. As the Daleks and their Pig Slaves attack, Solomon is exterminated by Dalek Caan. The Doctor, angered by Solomon's death, tells Caan to kill him as well, but Sec orders them to bring the Doctor in. Martha tries to go as well, but the Doctor makes her stay behind, giving her his psychic paper as he, along with Laszlo, leaves with the Daleks.
At the Dalek lab at the Empire State Building, the Doctor learns that Dalek Sec's plan is to continue the Dalek race by injecting humans of high intelligence with a mix of human and Dalek DNA, allowing their minds to be programmed as Daleks. However, as the task requires more energy than the human technology of 1930 can produce, Dalek Sec plans to use gamma strike from a solar flare that will occur within minutes, and forces the Doctor to help him finalise the energy system. As Sec announces that he plans to rid the intention of Dalek supremacy from these new beings, Jast and Caan believe Sec is a traitor to their race, and stage a mutiny, changing the DNA mix being fed into the humans into that of pure Dalek. The Doctor and Laszlo manage to escape during the chaos, heading for the top floors of the building. They manage to meet Martha, Tallulah, and Frank, who had used the psychic paper to gain entry from the building's human guards. After a brief reunion, they begin to search the blueprints of the building to learn how Sec planned to collect the gamma strike energy. Martha discovers the "Dalekanium" panels on the mast of the Empire State Building, and the Doctor quickly climbs up to dismount them, warning Martha of the Daleks and their Pig Slaves following them. As the Doctor struggles to remove the panels, Martha, with the help of the others, rigs several pieces of metal from the framework of the building into the elevator, acting as a long conductor of electricity when the gamma strike hits. Though Martha is successful and electrocutes the Pig Slaves in the elevator, the Doctor fails to remove the panels in time and instead grips the mast as the strike hits. The energy transfers into the human-Dalek shells and awakens the Dalek's new army.
Martha and the others recover the Doctor, and they flee to Tallulah's theater, with the human Dalek army following them in the sewers. As they are surrounded by the human Dalek army, they find that Dalek Thay and Jast have Sec in chains. As the two prepare to exterminate the Doctor, Sec tries to reason with them and then steps in the way of their blaster fire, sacrificing himself to save the Doctor. The Daleks order their army to kill the Doctor, but find that the humans are resisting; the Doctor, by exposing himself to the gamma strike, caused some of his Time Lord DNA to transfer to the human shells and give them freedom from Dalek control. The human Dalek army turn on Thay and Jast, killing them, but Dalek Caan, watching from the Empire State Building, activates a termination sequence and kills the rest of the army. The Doctor returns to the Dalek lab to face Caan, offering mercy and aid, but instead the Dalek escapes via his emergency temporal shift. As the Doctor regroups with the others, Laszlo begins to die, due to his partial transformation as a Pig Slave. The Doctor however, finds a cure to stabilise his condition, although it will not restore his human appearance. Laszlo and Tallulah are reunited, and learn from Frank that the people of Hooverville will take Laszlo in despite his looks. The Doctor and Martha finally return to Liberty Island and the Tardis, where the Doctor muses that there is to be yet another confrontation with the Daleks in their future.

Daleks in Manhattan

The Doctor and Martha, after leaving New New York, visit New York City in November 1930 (materialising the TARDIS at the base of the Statue of Liberty), before he returns Martha to her present. Stumbling across the mystery of people disappearing, they travel to the Hooverville community in Central Park and meet Solomon, the leader of the downtrodden residents, who explains more about the disappearances. When a wealthy businessman Mr Diagoras appears in Hooverville recruiting workers for sewer construction, the Doctor, Martha, Solomon, and a young man from Tennessee named Frank join up. As they explore the tunnels, the Doctor finds a mass of alien organic matter which he holds to analyse later. The group soon runs into a number of Pig Slaves and are forced to flee, though Frank is captured by the creatures.
The Doctor, Martha, and Solomon use a nearby ladder to escape and find themselves in a theater, being held at gunpoint by Tallulah, a showgirl demanding to know what happened to Laszlo, a stagehand she was dating. After the three explain their presence, the Doctor uses equipment in the theatre to create a matter analyser, while Martha helps to console Tallulah, learning that Laszlo disappeared similarly to the others a few weeks earlier. Tallulah goes on stage for her show, with Martha watching from the wings, when she spots a Pig Slave across the stage. Martha gives chase into the sewers, where she is captured by more Pig Slaves. The Doctor and Tallulah follow, but only find the sole Pig Slave Martha was chasing. Tallulah recognises him as her Laszlo, who has been incompletely transformed. They also encounter a Dalek, confirming the Doctor's analysis that shows the organic matter being from the planet Skaro. As the three follow the Dalek, they learn from Laszlo that the Daleks either transform those humans with low intelligence into the Pig Slaves, or take those of high intelligence aside for a "final experiment".
They find themselves under the incomplete Empire State Building, and the Doctor and Laszlo sneak inside to locate Martha. When the Doctor and Laszlo join both Martha and Frank with the rest of the high intelligence captives, they find that the Cult of Skaro are working on experiments to merge the Dalek and Human races so that the Dalek race can continue, assisted by Mr Diagoras during the construction of the Empire State Building. Dalek Sec plans to sacrifice himself to prove to the others that their evolution is possible. Dalek Sec, using energy collected by panels of "Dalekanium" attached to the mast of the Empire State Building, fuses himself to the body of Mr Diagoras, becoming a hybrid creature, and proclaiming himself as a "Human Dalek" and the future of the Dalek race.

Gridlock

The Doctor takes Martha with his TARDIS to the year five billion and fifty three in New New York on the planet New Earth, a place to which he had previously taken Rose Tyler. They end up in an alleyway where street traders are selling mood patches to help people deal with "The Motorway", but as they are investigating this, Martha is kidnapped at gun point and drugged by a young couple, Milo and Cheen. Once in their vehicle, they explain that Cheen is pregnant and that they needed three adult passengers to qualify for the high-occupancy vehicle lane, the "Fast Lane", and that they will drop Martha off when they reach their destination 10 miles (16 km) away in six years. Cheen also mentions rumours about something living down in the fast lane, saying that cars that go down there vanish, never to be seen again.
The Doctor chases after Martha's kidnappers and arrives at the (entirely enclosed) Motorway to find thousands of hover vans stuck in a tri-dimensional gridlock. The fumes in the air begin to affect the Doctor, but he is invited into the hover van of the cat person Thomas Kincade Brannigan and his human wife Valerie, who have a litter of kittens. The Doctor learns that the couple, along with all the other traffic on the road, has only travelled a short distance in several years, their vans having become their homes. Brannigan helps the Doctor to locate the vehicle containing his companion, heading towards the Fast Lane. As the Doctor tries to call the Police but gets put on hold and Brannigan refuses to put his family in danger, the Doctor decides to try and reach Martha himself and begins to jump down from lane to lane, breaking in and out of vans with his sonic screwdriver. Shortly after the Doctor leaves Brannigan's van, Novice Hame, who has been sent by the Face of Boe to locate the Doctor, enters Brannigan's van, chasing after him.
Martha, Milo, and Cheen drive into the Fast Lane, and begin to hear strange noises all around, and a nearby driver warns them to escape into the slow lanes before being eaten by the creatures that live in the fast lane, but Milo refuses. The Doctor, finding himself in a van just above the Fast Lane, looks out the bottom and discovers that the floor of the Motorway is filled with Macra, monstrous crab-like alien beings that once ruled an empire but now have devolved into feral, non-sentient beasts, who attempt to capture and eat those that fly in the Fast Lane. As the Doctor watches, Milo's van is nearly caught by one Macra's huge claw, but Martha realises that the beings are attracted by the light and motion generated by the van, and has Milo cut the power. This saves them from the beasts but leaves them with only a few minutes of breathable air in the van.
Novice Hame finally catches up with the Doctor and teleports him away forcefully to the Senate where the Face of Boe is waiting. Hame explains that a "Bliss" drug created by the pharmacists mutated into a virus that became airborne and wiped out the entire surface population, and only those in the Motorway were spared due to her actions to seal it off, keeping the travellers in constant traffic to avoid telling them the real problem. The Face of Boe has wired himself to the system to keep the Motorway operational. The Doctor determines that whatever danger that "Bliss" may have caused before has long passed, and works with Hame to try to power up the systems to unseal the Motorway but there is not enough energy left. The Face of Boe sacrifices his life energy to the system, allowing the ceiling of the Motorway to open, and the Doctor broadcasts a call for all drivers to escape that way and for Martha to come find him.
When Martha does so, the Doctor and Novice Hame are tending over the Face of Boe who is finally close to death; the glass container that encased it had shattered. The Doctor tries to encourage the Face of Boe to live, as both the Doctor and the Face of Boe are the last of their respective kinds, but with its dying breath it whispers the secret it promised to tell the Doctor before: "You are not alone". As the Doctor and Martha leave Hame to mourn, the Doctor does not try to postulate the meaning of those words, but explains to Martha that he is indeed the last Time Lord, and tells her all about Gallifrey as they return to the TARDIS.

The Shakespeare Code

A young woman is serenaded from her balcony by a lute-playing suitor. She bids him enter the house, but to his shock he finds it full of witching artefacts. The woman, Lilith, kisses him, and he finds her transformed into a wrinkled hag. She introduces her two "mothers", Doomfinger and Bloodtide, who appear, cackling; they lunge at the screaming youth, apparently devouring him.
Meanwhile, the TARDIS lands in Elizabethan London. Martha questions whether it is safe to walk around, citing such time travel concepts as the Grandfather paradox and a reference to the Ray Bradbury short story "A Sound of Thunder"; and also worrying about her safety as a black woman in a time when slavery still exists. The Doctor tells her not to worry. He declares that they have arrived in London in about 1599 and takes her to a performance at the Globe Theatre. At the end of the play, Love's Labour's Lost, Shakespeare announces that there will soon be a sequel called Love's Labour's Won. Lilith, using a poppet, influences Shakespeare to declare that the new play will premiere the following evening. Martha asks why she has never heard of Love's Labour's Won. The Doctor knows of the lost play and, decides to find out more about why it was never published — extending Martha's "one trip".
The two go to The Elephant, the inn where William Shakespeare is staying. They chat with the playwright, who intends to finish writing the final scene of Love Labour's Won that night. An instantly beguiled Shakespeare ("Hey, nonny nonny!") tries to woo Martha, describing her as "a queen of Afric" or a "blackamoor lady", which she finds slightly offensive. The Doctor claims she comes from "Freedonia" to explain her strange clothing and modern attitudes. Shakespeare sees past the Doctor's psychic paper, which the Doctor cites as proof of the man's genius.
Lynley, Master of the Revels, demands to see the script before he allows the play to proceed. When Shakespeare offers to show him the finished script in the morning, the official leaves proclaiming that he will ensure the play will never be performed. The trio of "witches" view the scene remotely by looking into a cauldron. Lilith, who works at the inn, secretly takes some of Lynley's hair and makes another poppet, which she plunges into a bucket of water. The Doctor, Martha, and Shakespeare hear a commotion in the street and run out, where they witness Lynley vomiting water. Lilith stabs the doll in the chest, and Lynley collapses, dead. The Doctor calmly announces that Lynley has died of an imbalance of the humours, and privately tells Martha that any other explanation would lead to panic about witchcraft. When Martha asks what did kill Lynley, the Doctor responds, "Witchcraft."
Martha and the Doctor stay overnight at the inn. The Doctor gives a disgruntled Martha mixed signals by casually sharing a bed with her, only to then openly bemoan the lack of Rose's insight. Meanwhile, Lilith entrances Shakespeare and, using a marionette, compels him to write a strange concluding paragraph to Love's Labour's Won. She is discovered by the landlady (also the Bard's lover), whom she frightens to death. On hearing another scream, the Doctor runs in and finds the body. Through the window, Martha sees a witch fly away on a broomstick.
In the morning the Doctor, Martha and Shakespeare proceed to the Globe Theatre, where the Doctor asks why the theatre has 14 sides. Shakespeare replies that the architect thought it would make sound carry well and mentions that he eventually went mad and talked of witches. The three then visit the architect, Peter Streete, in Bedlam Asylum. The Doctor helps Streete to emerge from his catatonia for long enough to reveal that the witches dictated the Globe's design to him. He also tells the Doctor that the witches were based in All Hallows Street.
The witches observe this interview through their cauldron. Doomfinger teleports to the cell and kills Peter with a touch. She threatens the other three but the Doctor works out who the witches really are. He names the creature as a Carrionite, which causes her to disappear. The Doctor explains that the Carrionites produce their magic through an ancient science based on the power of words.
Back at the Elephant, the Doctor deduces that the Carrionites intend to use the words of a genius — Shakespeare — to break their species out of eternal imprisonment when Love's Labours Won is performed. The Doctor tells Shakespeare to stop the play whilst he and Martha go to All Hallows Street to thwart the witches. The Doctor explains to Martha that if they don't stop the Carrionites, she and the rest of the human race will fade, much the same as Marty McFly. Shakespeare bursts on to the Globe's stage to make the announcement, but two of the Carrionites use one of their dolls to render him unconscious. The actors carry the playwright off stage and the performance proceeds.
The Doctor and Martha reach All Hallows Street and confront Lilith, who is expecting them. She confirms the Doctor's suspicions: the three Carrionites hope to gain entry for the rest of their species, eliminate the humans, begin a new empire on Earth and spread out from there. Martha, mimicking the Doctor's actions at Bedlam; tries to neutralise her by speaking the name Carrionite, but Lilith mocks her, since naming only works once. Instead, she names Martha Jones, rendering her unconscious.
Lilith tries to do the same to the Doctor, but it fails to affect him, as she is unable to discover his real name. She attempts to weaken him by naming "Rose", but he assures her that that name keeps him fighting. Lilith then feigns an attempt at seduction, which brings her close enough to the Doctor to steal a lock of his hair. Taking flight through the window, she attaches the hair to a doll — which the Doctor explains is essentially a DNA replication module — and stabs it in the heart, whereupon the Doctor collapses. Assuming that he is dead, Lilith flies to the Globe. Martha wakes, and helps the Doctor restart his left heart before the duo race to the Globe.
The actors have already spoken the last lines of the play, a series of directions and instructions that have opened a portal allowing the Carrionites back into the universe. The Doctor tells Shakespeare that only he can find the words to close the portal. Shakespeare improvises a short rhyming stanza but is stuck for a final word. Martha comes up with Expelliarmus which is shouted at the Carrionites (as shown in the picture). The Carrionites — together with all the extant copies of Love's Labour's Won — hence, are sucked back through the closing portal. Martha, Shakespeare and the actors from the play are left to take the applause of the audience who believe it all to be special effects. The Doctor meanwhile finds the three witches trapped, screaming in their own crystal ball and appropriates it for safe keeping in a dark attic of the TARDIS.
In the morning, Shakespeare flirts once more with Martha and with the Doctor. He reveals his deduction that the Doctor is not of the Earth and that Martha is from the future, once again proving his genius. For his "Dark Lady", he produces the sonnet, "Shall I compare thee to a summer's day?" in her honour, but is interrupted when two of his actors burst in, heralding the arrival of the Queen. Queen Elizabeth enters, recognises the Doctor as her "sworn enemy" and declares, "Off with his head!" The Doctor is surprised at her outburst, since he says he has not yet met the Queen, but comments that he is looking forward to finding out what he will do to offend her. He and Martha flee to the TARDIS, slamming the door just as an arrow embeds itself in the TARDIS's exterior before dematerialisation.

Smith and Jones

Martha Jones is a particularly astute medical student. On her way into work at a London hospital, she bumps into a strange man (the Doctor) who pauses in front of her and removes his tie, saying, "Like so, see?" When she arrives at work, she again meets the Doctor, who is lying in bed posing as a patient under the name John Smith. He is unaware of seeing Martha earlier in the morning.
A brutal mercenary police force, the rhinoceros-like Judoon, who have no jurisdiction on Earth, transport the hospital to the Moon using a "H2O Scoop" in order to apprehend and execute Florence Finnegan, a shapeshifting, bloodsucking Plasmavore with the ability to appear as whatever species whose blood she consumes. As soon as the hospital is in position, the cylindrical Judoon ships land and the troopers march into the building (due to their bodily shape and heavy footwear, their motion is referred to throughout the script as "yomping"). The Judoon begin scanning everyone in the hospital, cataloguing the humans whilst attempting to find the non-human criminal. Finnegan attempts to evade capture by sucking the blood of humans. Her first victim is Mr Stoker, the head doctor, and consequently she registers as a human when scanned by Judoons. The Doctor is identified as "non-human" and thus is thought to be the fugitive by the Judoon, forcing him and Martha, with whom he teamed up shortly after arriving on the Moon, to flee.
The Doctor and Martha discover Stoker's body drained of blood which confirms the Doctor's suspicion that a Plasmavore is in the hospital, this in turn explaining the Doctor's presence there to the audience. The Doctor kisses Martha, performing a "genetic transfer" which provides her with traces of contact with a non-human. He leaves her behind to be fully scanned by Judoon, providing him with more time as he goes in pursuit of the Plasmavore. Thinking the Doctor is human, Finnegan sucks his blood causing him to collapse unconscious, presumed dead. Judoons arrive and confirm the non-human is deceased. Martha enters, realises that Finnegan has absorbed non-human blood, grabs a Judoon's scanner and identifies Finnegan as non-human. Confirming Finnegan is a Plasmavore, the Judoon execute her for the murder of the child princess of Padrivole Regency Nine.
Before expiring, Finnegan modified an MRI scanner to make it destroy all life on the Moon and on the half of Earth facing the Moon except herself, thus allowing her to use the Judoon ships to escape. Their job done, the Judoon evacuate. Martha uses CPR on the Doctor's two hearts and manages to revive him, and he turns off the scanner. Oxygen levels are low and the occupants of the hospital are near death but, as they depart, the Judoon return the hospital safely to Earth.
Martha attends her brother's birthday party, but it breaks down into a family row. She notices the Doctor outside and follows him. He goes to the TARDIS and invites Martha to go on a trip with him as a reward for her help. Martha hesitates until the Doctor says he can travel in time as well, and proves it by travelling back to the previous morning and taking off his tie in front of Martha (later explaining, "Crossing into established events is strictly forbidden — except for cheap tricks"). After this demonstration, Martha steps into the TARDIS (noting that it's bigger on the inside). The Doctor refers to Rose Tyler and emphasises that Martha is not replacing her but is only going to get one trip as he prefers to travel alone.

The Runaway Bride

A bride-to-be, Donna Noble, vanishes while walking up the aisle and materialises in the TARDIS just after The Doctor has made his farewells to Rose Tyler. Both are astounded by this event. Donna, thinking he has somehow kidnapped her, demands the Doctor return her to the church in Chiswick but he accidentally lands the TARDIS near Oxford Street instead.
Donna storms out of the TARDIS and tries to contact her family through a public telephone, while the Doctor wonders how she could have got aboard. He then recognises masked Santas nearby as the robotic scavengers from the previous year's Christmas, levelling their weapons disguised as musical instruments at him. He distracts them by using his sonic screwdriver on a nearby ATM to make it spit out money and causing a crazed rush from the nearby crowd, and then goes off in search of Donna. She has managed to collect some money and is taking off in a cab, but its driver turns out to be another one of the robotic Santas. The Doctor gives chase by flying the TARDIS directly over the motorway and rescues her. However, such an endeavour has put a strain on the TARDIS, and he cannot use it for some time. The Doctor gives Donna a ring to prevent the Santas from tracking her and tries to figure out why she was targeted earlier. He learns that she works at a security firm called H.C. Clements, where she met her husband-to-be, Lance Bennett.
The Doctor takes Donna to her reception, to the relief of Lance, her family and their friends. The Doctor learns that H.C. Clements is owned by the Torchwood Institute, and, through footage taken by the photographer at the wedding earlier, that Donna was turned into Huon particles, a source of energy that hasn't existed for billions of years. This cannot be masked by the ring he gave her earlier, and the reception hall is surrounded by the Santas, who have also rigged a Christmas tree with explosive ornaments. Using the sound system at the reception and his sonic screwdriver, the Doctor is able to shake apart the robots, and trace the source of their control to a star-shaped spaceship hanging above the city, but shortly loses its signal.
The Doctor asks Lance to take him and Donna to H.C. Clements, wondering who controls the firm since Torchwood One's dissolution in the Battle of Canary Wharf. He discovers a secret basement level and the three of them travel to it, finding themselves in a long tunnel that eventually leads to the Thames Barrier. There, the Doctor discovers a laboratory where Huon particles have been manufactured and stored in liquid form. The Doctor determines that Donna was saturated in them so that due to the stress of her wedding day, she would cause the particles to catalyse and activate for an unknown purpose. However, the process pulled her into the TARDIS's own source of Huon particles.
A large hole also extends across the room, the Doctor surmising that it was dug out by Torchwood's laser technology and extending to the centre of the Earth. As they explore, a half-humanoid, half-spider creature teleports, which the Doctor identifies as one of the Racnoss, an alien race thought to have been wiped out billions of years ago. The Racnoss, which calls itself the Empress, has fashioned a large web above the pit, where the body of H.C. Clements still hangs. Lance reveals that he has been working for the Racness and that he was the one who saturated Donna with Huon particles by serving her spiked coffee in the office - unintentionally causing Donna to fall in love with him and bully him into proposing. When the Doctor and a heart-broken Donna escape with the TARDIS, the Empress decides to use Lance as she intended to use Donna, and begins force-feeding him the particles.
The Doctor takes the TARDIS back in time to the creation of the Earth to discover the final piece of the puzzle: the planet actually formed around a Racnoss spaceship which is still in its core. The Empress's goal is to use the Huon particles to reawaken those still on board and devour the human race. The Doctor and Donna, who has been lifted out of her gloom by the majestic spectacle, return to the laboratory where Donna is immediately captured into the Empress's web, while the Doctor is held at gunpoint. The Empress begins to activate the Huon particles and drops Lance into the pit as food for her fellow Racnoss, who have awoken and are beginning to ascend to the surface.
Meanwhile, her ship begins to descend and attacks London. The Doctor manages to sneak back into the laboratory and issues the Racnoss a final offer, to take her and her kind to a planet where they will not threaten anyone. When she refuses, having not realised that the Doctor is a Time Lord, he identifies himself as from Gallifrey (gaining a reaction of outrage and fear from the Empress, who accuses the Time Lords of having murdered the Racnoss) and uses some of the explosive Christmas ornaments to burst apart the walls. Water from the River Thames bursts into the building and floods the well, drowning the Racnoss at the Earth's centre. Donna urges a vengeful Doctor to leave and they escape into the TARDIS once more. The Empress teleports back to her now defenceless ship, shortly before it gets blown out of the sky by the army.
The Doctor returns Donna home but she is desolate, having lost her job and her fiancé the same evening. She declines an invitation to join him in the TARDIS but suggests he find someone else to calm him down, as she did earlier in battle. The Doctor tells her briefly about Rose, and then disappears back into the TARDIS.