Villanelle has disappeared, and Eve is left reeling, having no idea if the woman she stabbed is alive or dead. With both of them in deep trouble, Eve has to find Villanelle before someone else does. But unfortunately, she's not the only person looking for her.

Eve is a bored, whip-smart, pay-grade MI5 security officer whose desk-bound job doesn't fulfill her fantasies of being a spy. Villanelle is a mercurial, talented killer who clings to the luxuries her violent job affords her. Everything changes when they cross paths.