
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.
7.5
7.4
7.8
7.7
7.6
5.8
7.2
8.1
6.0
6.3
6.6
5.9
6.2
7.1
6.7
8.0
5.9
7.7