The Doctor arrives on Earth after a violent regeneration, only something's not right. Upon finding out there was another Doctor before him who completed his regeneration cycle, there is an old foe waiting for him in orbit.
The Doctor has been taken out of time and placed into a prison with his future incarnation. They must work together to discover what happened to James and Henry with the Savalona King, before their time-lines disrupts permanently.
Upon being given their first mission, the Doctor, James and Henry are sent to a spaceship hidden behind an asteroid, where an old foe is aboard to greet the Doctor.
After answering a distress call, the Doctor and his companions meet Henry's doppelganger, Harry Woodman, who's life is being controlled by an extraterrestrial force.
After discovering a series of coincidental events, the Doctor decides he must take action. However, disaster strikes when the Doctor and the TARDIS are wiped from existence, leaving Julia and Henry to investigate how this happened.
Having his regenerations removed and sent off on his final mission, the Doctor, along with his human companions, must find any way out they can of the trap they find themselves in.
