The Doctor and Clara land on a damaged Russian Submarine in 1983 as it spirals out of control into the ocean depths. An alien creature is loose on board, having escaped from a block of Arctic ice. With tempers flaring and a cargo of nuclear weapons on board, it’s not just the crew but the whole of humanity at stake!
Airs on ABC tonight at 7.30 p.m
Go behind the scenes of the Cold War with Matt Smith and Jenna-Louise Coleman, and writers Mark Gatiss and Steven Moffat.