Vadim returns to Russia where his allegiances are tested, leading him to a risky stunt.
A young intern’s first day at GCHQ coincides with a major cyberattack on the UK. To win her superiors’ trust, she breaks ranks to analyse the malware code without permission…
An alien warlord sets a twisted plan in motion in order to ensure his survival on a remote Army outpost, and the Doctor may have to do something unthinkable.
The Doctor and Clara save the frightened crew from a threat in an underwater base, but the Doctor questions the haunting.
