A dusty, half-forgotten outpost on Mars is the last place you'd expect a breakthrough in law enforcement—but that's exactly where a crate arrives carrying an experimental police robot named Ned. Sergeant Kelly quickly learns this isn't just any piece of machinery; Ned is programmed to enforce the law with unwavering precision and no sense of local "arrangements," especially those involving Nineport's criminal kingpin, China Joe. As Ned begins making arrests no human cop would dare attempt, the fragile order of the settlement cracks apart, forcing Kelly to choose between survival and duty.

Arm of the Law is one of Harry Harrison's sharp, witty explorations of technology colliding with human frailty. With fast pacing, dry humor, and clever twists, Harrison drops readers into a frontier town where justice arrives in the form of a steel rookie who salutes too crisply and fires a cannon from between his eyes.

Harry Harrison (1925–2012) was a defining voice of mid-century science fiction, celebrated for blending adventure, humor, and sharp social commentary. Best known for The Stainless Steel Rat series, Make Room! Make Room!, and dozens of short stories, Harrison's work seamlessly weaves satire into futurism. His stories often explore the unintended consequences of technology, making Arm of the Law a perfect example of his signature style.