A female assassin is taken into custody in Russia, and Eve and Carolyn head out to Moscow to negotiate access. She could hold the key to the organization that runs Villanelle. Meanwhile, Villanelle is smuggled into the same Russian jail. It's a grim and brutal place, where not even Villanelle is safe.

Tensions are running high as the situation in Moscow escalates, and Eve starts to question who she can trust. Despite the danger, with her sights firmly set on Villanelle, Eve goes rogue. With both women under pressure, the stakes are higher than ever.

Villanelle's mission is proving anything but straightforward, forcing her to take drastic measures. Meanwhile, Eve makes a shocking discovery, which leads her right to Villanelle and an electrifying confrontation from which neither will emerge unscathed.