Overview
In a Mars base, the inhabitants are being infected by a mysterious water creature which takes over its victims. The Doctor is thrust into the middle of this catastrophe, knowing a larger one is waiting around the corner.
Cast
- David Tennant as The Doctor
- Lindsay Duncan as Captain Adelaide Brooke
- Peter O'Brien as Ed Gold
- Sharon Duncan-Brewster as Maggie Cain
- Gemma Chan as Mia Bennett
- Aleksandar Mikic as Yuri Kerenski
- Michael Goldsmith as Roman Groom
- Cosima Shaw as Steffi Ehrlich
- Joplin Sibtain as Tarak Ital
- Alan Ruscoe as Andy Stone