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.

Top Cast

David Tennant

The Doctor

Lindsay Duncan

Captain Adelaide Brooke

Peter O'Brien

Ed Gold

Sharon Duncan-Brewster

Maggie Cain

Gemma Chan

Mia Bennett

Aleksandar Mikic

Yuri Kerenski

Michael Goldsmith

Roman Groom

Cosima Shaw

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