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. Eve, in emotional turmoil, now knows how high the stakes are.
Eve's life as a spy is not adding up to what she had hoped it would be when she started. She is a bored, very smart, MI5 security officer who is very desk-bound. Villanelle is a very talented hugger, mercurial in mood, who clings to the luxuries of her job. Eve and Villanelle go head to head in a fierce game of cat and mouse, each woman equally obsessed with the other as Eve is tasked with hunting down the psychopathic assassin.