A bored MI5 security officer yearns for more excitement. When a Russian politician is murdered, she is tasked with protecting the only witness and soon finds herself on a collision course with a violent and extraordinary assassin.
In the aftermath of her recent assignment, Villanelle is ordered to take a break. Never one to do as she's told, she goes ahead with her next mission regardless. Meanwhile, Eve is given a dream opportunity to join a secret MI6 unit tracking Villanelle and the shady organization she works for.
When Villanelle kills a Chinese colonel at a kink clinic in Berlin, Eve and Bill travel out to investigate. While Eve and Bill chase up a number of promising leads, Villanelle enjoys the cat-and-mouse of their proximity. But as they draw closer, Eve comes to realize that this is much more than a game.
Intel from Berlin points to the existence of a mole, prompting Eve to undertake her first surveillance operation; Villanelle is sent to England to eliminate a member of British Intelligence. Villanelle wonders, could it be Eve? Meanwhile Eve, in emotional turmoil, now knows how high the stakes are.
Having survived a terrifying close call with Villanelle, Eve now has the mole ensconced in a safe house and is buzzing. They have an exciting opportunity to glean information and crack this thing open.
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.
Eve is reeling from her act of violence against Villanelle and doesn't know whether she is alive or dead. A paranoid and severely injured Villanelle manages to get herself to the hospital for treatment. Carolyn approaches Eve with an intriguing opportunity.
Eve is attempting to rebuild her life, having been shot by Villanelle. Villanelle is also moving on, until she is approached by an old foe. Carolyn is being undermined at work and Kenny can’t leave his own investigation into The Twelve alone.
Villanelle agrees to a job which will take her back to London. Carolyn's Moscow contacts come in use when Eve and the Bitter Pill team unravel a potential lead to The Twelve. Konstantin finds himself under pressure from all sides.
Eve is trying to patch up things with Niko. Villanelle receives good news about her upcoming promotion but can't shake the feeling there's still something missing from her life. Dasha seeks a solution to Villanelle's erratic behavior.