Doctor: David Tennant (Tenth Doctor)
Companions: Freema Agyeman (Martha Jones)
John Barrowman (Jack Harkness)
Derek Jacobi – Professor Yana
Chipo Chung – Chantho
René Zagger – Padra
Neil Reidman – Lieutenant Atillo
Paul Marc Davis – Chieftain
Robert Forknall – Guard
John Bell – Creet
Deborah Maclaren – Kistane
Abigail Canton – Wiry Woman
John Simm – The Master
Directed by Graeme Harper
Written by Russell T Davies
Script editor Simon Winstone
Produced by Phil Collinson
Executive producer(s) Russell T Davies
Incidental music composer Murray Gold
Production code 3.11
Series Series 3
Length 1st of 3-part story, 45 minutes
Originally broadcast 16 June 2007
The TARDIS lands in Cardiff to refuel from the Cardiff Rift. The Doctor states that this will only take twenty seconds, noting that the Rift has been active recently. The Doctor sees Captain Jack Harkness racing towards the TARDIS and dematerialises. Jack grabs on to the outer shell, causing the TARDIS to fly to the end of the universe trying to shake him off. Upon arrival, a panicked Martha notes that Jack is dead. Several seconds later he revives and introduces himself to Martha. He tells them that he wanted to find the Doctor, so he returned to Earth using a vortex manipulator but was stranded in the 19th century. Jack decided to base himself at the Cardiff Rift and waited, knowing the Doctor would eventually land there to refuel. As they explore the planet they find an abandoned city and the Doctor notes that they are nearing the heat death of the universe. They encounter a lone human running for his life from the Futurekind, cannibalistic humanoids that are attempting to eat him. He is attempting to reach a nearby missile silo to get transport to "Utopia", the last hope of the human race.
The Doctor, Jack, and Martha help the man reach the silo. While there they meet the elderly Professor Yana and his insectoid assistant Chantho. The Professor asks the Doctor to look at their rocket engine to determine why it won't launch, and the Doctor helps him repair it. During the repairs, the Professor repeatedly hears a rhythmic drumbeat in his head that causes him to become distracted. He explains that he has heard the drums for as long as he can remember, but he does not know what they mean. When the rocket is ready to launch, the survivors all file inside and the Doctor uses his TARDIS to help power up the engines. One of the Futurekind reveals herself and destroys some control panels, causing an overload that shorts the system out. A man attempting to remove the engine clamps is killed, and Captain Jack is enlisted to enter the highly irradiated room to finish the job.
While Jack is inside working, the Doctor admits he abandoned him purposely on Satellite 5 (in The Parting of the Ways) because of Jack's immortality, which disturbed him. They discuss the Doctor's newest regeneration, and the words trigger a reaction in Professor Yana. He begins to hear the drumbeat in his head louder and louder, and he has to sit down to recover. Jack finishes his work and the rocket is ready to launch. The Professor reveals that it can only be triggered from the silo, meaning that he and Chantho were planning on staying behind. The launch sequence begins, and Martha goes to check on Professor Yana. She is terrified to see that he possesses a fob watch identical to the one the Doctor possessed in "Human Nature"/"The Family of Blood". She unintentionally draws the Professor's attention to it, overriding its perception filter. She rushes to tell the Doctor about it as the Professor is suddenly overcome by voices coming from the watch.
The Doctor initiates the launch sequence of the rocket at the same time that the Professor opens the fob watch. A frantic Doctor runs back to the control room, but the Professor locks down the silo and opens the outer gates. The Futurekind swarm into the base and rush toward the Doctor, Jack, and Martha. Chantho confronts the Professor and asks what he is doing, and he replies by telling her that his name is The Master. He attacks Chantho with a live electric cable, but she manages to shoot him before she dies. An injured Master stumbles into the TARDIS. The Doctor reaches the control as the Master deadlocks the doors. Dying from Chantho's shot, the Master declares he will be young and strong like the Doctor and proceeds to regenerate. The newly regenerated Master taunts the Doctor over the intercom in a voice that Martha recognises. The Master begins to dematerialize the TARDIS, and the Doctor uses his sonic screwdriver to lock the TARDIS coordinates between there and the last place it visited. The episode ends on a cliffhanger as the TARDIS disappears, stranding the Doctor, Martha, and Jack with the Futurekind about to break the door down.