Tooth and Claw

The Doctor attempts to take Rose to Sheffield in 1979 to see Ian Dury in concert, but ends up in the Scottish moors in 1879. They encounter a carriage carrying Queen Victoria, who has been forced to travel by roads to Balmoral Castle as a fallen tree has blocked the train line to Aberdeen, feared to be a potential assassination attempt. The Doctor poses as Dr. James McCrimmon using his psychic paper, and the Queen invites him and Rose to join her as they travel to the Torchwood Estate, a favourite of her late consort Prince Albert, to spend the night. The royal party is unaware that the Torchwood Estate has been captured by a group of monks from a monastery in St. Catherine's Glen led by Father Angelo, forcing its owner, Sir Robert MacLeish, to play into their ruse as they take the place of the house's servants and guards. The monks, having arranged for the fallen tree to force the Queen to the estate, have brought a man inflicted with a form of lycanthropy, hoping to pass its nature to the Queen and create a new "Empire of the Wolf".
The Doctor soon realizes the trap they have fallen into, and helps to save Rose, the Queen, and Sir Robert from Father Angelo's men and the werewolf by taking shelter in the estate's library, its wood coated with oil of mistletoe wood to stave off the beast. They study the library and discover evidence collected by Sir Robert's father, a polymath, and Prince Albert that indicate the werewolf is really the current form of an alien species that fell to earth in 1540 near the monastery, surviving by passing its lycanthropic form from human to human. The Doctor also realizes that the estate was designed as a trap for the werewolf, as by use of its strange telescope along with the Queen's Koh-i-Noor diamond, its cut fashioned by Prince Albert, they can force the werewolf to revert to human form and destroy the alien lifeform.Sir Robert sacrifices himself to allow the Doctor, Rose, and the Queen to prepare the telescope in the Observatory. They are able to trap the werewolf in the concentrated light of the full moon collected by the diamond. The transformed human being begs for the Doctor to kill him by increasing the power of the light concentration, which he obliges. As they recover, the Queen finds a small cut she believes came from a wood splinter, but the Doctor remarks to Rose that all her children will carry a form of haemophilia, and that perhaps this was simply a Victorian euphemism for lycanthropy. The next day, the Queen dubs the Doctor and Rose with royal titles before banishing them from the British Empire. The Queen is appalled and outraged by the unholy sort of lifestyle the Doctor and Rose share. In honor of Sir Robert's sacrifice and his father's ingenuity, she orders the creation of the Torchwood Institute to help defend England from further alien attacks.