The story follows , a senior contract killer who has spent 45 years working as a "disease control specialist"—a euphemism for an assassin. Living a solitary life with her aging dog, Deadweight , she begins to feel the physical and emotional toll of her profession.

: It examines the struggle to find meaning beyond one's profession and the fight against being discarded by a corporate, "youth-obsessed" world.

: The novel explores how elderly women are often ignored by society, a trait Hornclaw uses to her advantage as a killer.