The breathless chase through time and space continues, with the Doctor and Alice on the run over a crime committed by one of his previous incarnations! Things get complicated - quick - as a chainsword-wielding freelancer boards the TARDIS. Is he friend, foe, or something even worse? With only minutes left before the implant in Alice's head gives their location away to the transtemporal bounty hunters on their tail, the Doctor won't have time to weigh his options - and the consequences will be heavy!