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.
演员: David Tennant
/ Lindsay Duncan
/ 陈静
/ Peter O'Brien
/ Sharon Duncan-Brewster
/ Joplin Sibtain
/ Max Bollinger
/ Charles De'Ath
