MI5 security officer Eve Polastri is bored in her job and yearns for a more exciting life. When a Russian politician is murdered, Eve 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. Meanwhile, Eve is given the chance to join a secret MI6 unit tracking Villanelle and the organisation she works for.

When Villanelle kills a Chinese colonel in Berlin, Eve and Bill travel out to investigate. While Eve and Bill chase up a number of leads, Villanelle enjoys the cat-and-mouse of their proximity; but as they draw closer, Eve comes to realise 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. Meanwhile, Villanelle is sent to England to eliminate a member of British Intelligence. Villanelle wonders, could it be Eve?

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.

A female assassin is taken into custody in Russia, and Eve and Carolyn head out to Moscow to negotiate access. 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.

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.

Carolyn introduces Eve to her new team before Eve briefs them on the Villanelle case. Villanelle, needing to lie low while she recovers, finds a good Samaritan to take her in and care for her.

Villanelle's new circumstances are looking bleak, while Eve makes a dangerous deal with an old acquaintance. Villanelle is surprised when she is approached by a figure from her past.

Villanelle decides to take matters into her own hands on a trip to Amsterdam. Carolyn is called in to face the music with her boss. After the discovery of another dead body, Eve and her new team make a break in their case.

The MI6 team make a pact with the devil in order to get information from The Ghost. A visitor from Broadmoor comes with a dire warning, while Eve and Villanelle find themselves closer than ever.

Villanelle uses her unrivalled infiltration skills to immerse herself in the world of a new target. Their relationship on the rocks, Eve and Niko confront each other about their future.

Villanelle dives deep into the dangerous world of her target under the guise of her newfound persona, Billie. Eve may have worrying competition for Villanelle's affections.

Eve's mission is disastrously compromised. Carolyn briefs Eve on her current status as an employee of the British government and leaves Eve's future in her own hands. Villanelle does everything she can in order to get to her ultimate target.

After being shot by Villanelle, Eve is attempting to rebuild her life; 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.

Eve strikes up an unlikely alliance with Kenny's colleagues at the Bitter Pill, while Villanelle finds that management isn't all it's cracked up to be.

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.

It's Eve's birthday, and she's trying to patch up things with Niko. Villanelle receives good news about her upcoming promotion but can't shake the feeling that there's still something missing from her life. Dasha seeks a solution to Villanelle's erratic behaviour.

Villanelle returns to Russia to try to find her family, hoping that perhaps a new connection to her roots will give her back what has been missing in her life.

As the investigation continues, Carolyn finds out that information is being withheld by those close to her. Eve finds a lead which might bring her closer to Villanelle, but Villanelle has had enough and decides on a different path.

Eve finds a clue to Villanelle's whereabouts in the most unlikely of places. Villanelle and Dasha work together on a kill. Konstantin, meanwhile, is crumbling under the pressure.

Konstantin makes a break for it, while Eve and Villanelle try to work out what the future may hold for them - together or apart.

Eve is on a revenge mission against The Twelve. She has a lead and needs to track her down via one of her assassins. Villanelle wants to change; so endears herself to a church community. Carolyn is focused on getting back in the game.

Eve locates Helene who may be useful in her revenge mission against The Twelve. Villanelle's quest for change goes awry. Carolyn is pushed aside by MI6 so is forced to seek cooperation elsewhere - she needs to find out who ordered Kenny's hit.

Having stalked Helene, a new lead allows Eve to uncover a name in The Twelve's top tier. Villanelle is rejected by Eve when she seeks help. Operating abroad, Carolyn discovers more promising intel on a spate of torturous murders linked to The Twelve.

Eve struggles to identify her lead in The Twelve. Villanelle gets her mojo back - she decides to be good by embracing what she's good at - killing! Carolyn discovers an old acquaintance in Cuba and decides to go rogue.

Eve delves into the past of her target and unearths some secrets. Villanelle re-embraces killing; she has a try at doing it altruistically before deciding to kill those who oppressed her. Carolyn tracks down a top member of The Twelve.

Eve and Villanelle reunite before parting to pursue their own missions, which leads Villanelle to another assassin in The Twelve. Eve moves closer to achieving her revenge mission. Carolyn is forced to face a ghost from her past.

Eve takes on an even bigger revenge mission against The Twelve and realises she may need Villanelle's help. Villanelle has a dalliance with the new assassin. Carolyn's latest string of intel may lead her home.

Eve and Villanelle focus on making a seismic stab at The Twelve, risking their own lives. Carolyn arrives home as a traitor, she has a finite amount of time to use her intel as leverage to get herself back in the game.