In the crime-plagued city of Ergastulum, a group of humans possessing super strength and speed, known as "twilights," exists. These twilights characterize the city through their ongoing tension with ordinary humans, while powerful local factions—the Corsica Family, the Monroe Family, the Cristiano Family, and the Paulklee Guild—employ them to uphold the city's fragile equilibrium. Introducing the charming human Worick Arcangelo and the deaf twilight Nicolas Brown, two longtime friends and business partners belonging to the neutral group "The Handymen." Operating as hired muscle, they accept nearly any job offered to them in order to survive financially. One day, they receive what appears to be a standard assignment from the police: eliminate a rival pimp and his prostitute. However, this job proves to be more complex than it initially appears, leading the duo onto a perilous course and sparking events that could permanently alter the very structure of Ergastulum.