Cold War is the eighth episode of Series 7. Eleven (Matt Smith) and Pancakes (Jenna Coleman) land on a Soviet submarine in 1983 during the Cold War where the Ice Warrior Grand Marshal Skaldak (voiced by Brick Niggs) breaks loose and seeks vengeance against humanity for having to be in an episode written by Gatiss.
For an episode featuring a badass alien in Soviet submarine, the episode is remarkably boring. What a waste of concept, bravo Gatiss.
For one scene a character breaks established Doctor Who convention of speaking British English no matter where you are and lapses into speaking Russian. Choice of words indicates he thinks there's a woman frozen in ice - no wonder he was so eager to thaw it. Too bad he found an Ice Warrior instead (Ice Warriors are kinda boring, really, Doctor Who can do better than lizards from Mars).
The Ice Warrior presents a VNA level dilemma. Abandoned by his race and believing they are all dead, in a state of emotional trauma, he threatens to hit the big red button on the nuclear missile launch and thus ignite the Cold War into a Hot Mess. With Clara Who's sweet and saintly empathetic words failing to get through, it seems like the Doctor will be forced to kill the motherfucker where he stands to prevent the end of the world.
Don't worry though. Literally as he's about to press it, the missing Ice Warrior spaceship shows up to beam him away. They were just a bit late that's all. Thanks Gatiss, you had us panicking for a sec there.
The episode ends with characters laughing, completely without irony, on the events that got multiple people killed.