Psychopathic Villanelle—a young and prolific assassin—leaves a trail of high-profile murders across several countries. MI5 officer Eve Polastri connects a new assassination in Vienna to a series of such killings which she has been researching in her own time.
Villanelle is elevated to Keeper by Hélène, a specialist of the Twelve, and requested to kill a Romanian lawmaker. Baffled and disappointed that the work is the same, she moves toward Konstantin and requests to join his arrangement to flee.
Villanelle approaches Carolyn and offers to turn into a source for MI6; Carolyn rejects her when she can’t give any data. Villanelle then, at that point approaches Eve and requests that she recover a bundle Konstantin had stowed away to help his departure.
Following her assignment in Bulgaria, Villanelle’s handler Konstantin is concerned about her increasing recklessness. He informs her that a covert MI6 task force, led by Eve, is investigating her string of assassinations
With new information about Aaron Peel, Villanelle goes undercover as a New Yorker named Billie to befriend Aaron’s sister, Amber but there is conflict between Villanelle and Aaron.