Having barely survived being shot by Villanelle, Eve Polastri has retreated into obscurity, living under a new identity and mourning the strange connection she lost. Meanwhile, Villanelle, believing Eve dead, runs a training school for assassins in St. Petersburg, yet finds herself haunted by memories of her rival. When whispers of the Twelve's activities resurface, the two women are drawn back together, forging an uneasy, darkly intimate alliance. Crossing Europe in pursuit of the shadowy organization's leaders, they finally converge on a remote Baltic island, where love, obsession, and vengeance collide in a lethal final reckoning.