[4] While answering a public disturbance call on Pearl Street, NYPD Detective John Tallow's partner of twenty years is killed by a depressed apartment tenant.

Eventually he unravels a conspiracy that ties a banker, the Assistant Chief of Police, and the CEO of a private security company to the mysterious killer, using him as a hitman for their own personal gain.

Tallow speaks with The Hunter, in prison and taking anti-psychotics for his schizophrenia, and confirms his suspicion that the room of guns was a Native American wampum, a kind of symbolic language made with beads.

Ellis stated in 2012 that rights for Gun Machine had been purchased by the 20th Century Fox TV and Chernin Entertainment, with the intent of turning it into a television series.

[10] The New York Times gave a mixed review, calling it a "pleasingly quirky crime thriller" while stating that the ending felt "a little unsatisfying" due to how neatly everything was wrapped up.