Paul McGann (The Doctor), Olivia Vinall (Sheena), Nimmy March (Rupa Maguire), David Ganly (Quarren Maguire), Sean Murray (Captain Darvor), Hywel Morgan (Koloth / Jefferson), Laurence Kennedy (Purser Lunney / Aymor / Chancellor), Rakhee Thakrar (Bliss). Nicholas Briggs (the Daleks)
The Doctor and his companion, Sheena, land the TARDIS on the glamorous luxury space-liner Theseus just as it’s about to leave the Jupiter space-port. An opportunity for a holiday presents itself – and it’s one they’re very glad to take.
But when a disturbance catches their attention, they realise sinister events are taking place on board. Passengers are vanishing on every trip. And unless they’re careful They may be next.
Can The Doctor and Emma solve the mystery? Or is there something else They should be worrying about?
Due to the temporal anomalies caused by the Time War, The Doctor lands on the Theseus when it is a luxury liner taking passengers on holiday, cutting costs by sacrificing victims to pan-dimensional beings that live on certain hyperspace lanes to prevent the entire ship being destroyed. Its history is changed to a converted liner that is transporting refugees away from the Time War, with the ‘sacrifices’ being ‘volunteers’.
As another side-effect of the temporal anomalies, The Doctor arrives on the Theseus accompanied by Sheena, who then changes to Emma, and finally becomes Louise before disappearing completely. By the time The Doctor realises that his companion is changing, he also observes that he cannot recall when they started travelling together.
This story’s title and concept is based on the Ship of Theseus paradox, which questions whether an object, if all its components are replaced, is essentially the same object. This idea would later be referenced in regards to the Half-Face Man from Deep Breath.