Nicholas Elliott (Damian Lewis) and Lily Thomas (Anna Maxwell Martin) race to interrogate Anthony Blunt before the CIA can intervene. During the high-stakes questioning, Blunt eventually confesses that his instructions in case of exposure were to seek help from Sir Roger Hollis , the head of MI5.

The episode follows two main threads as the walls close in on suspected traitors:

The fifth episode of the limited series , titled "Snow," serves as the penultimate chapter where key investigations into Soviet infiltration of British intelligence reach a boiling point. ❄️ Plot Summary