A murder in a world where murder is impossible. Gesicht, a robot built to solve the unsolvable, discovers that some kinds of evil don't need hands to kill. The mystery isn't what happened, it's what hate becomes when it has centuries to think.

A murder takes place in an orderly world where robots are built so that they cannot kill humans. Gesicht, an android detective with Europol, investigates the death of Montblanc, a retired robot war hero, and a string of robot and human deaths that follows. No trace of a human turns up at the scene, and the evidence points to a robot killer, which would be the first in eight years. When another retired war robot is destroyed, Gesicht sees a pattern: both victims belonged to a group of the seven most powerful war machines ever made. To protect the five who remain, he turns to Atom, an advanced android who looks like a human boy. Their hunt leads toward a hatred bent on bringing destruction to the world. The eight-episode ONA is a psychological sci-fi mystery thriller with mecha elements, adapted from Naoki Urasawa's manga reimagining of a story arc from Osamu Tezuka's Tetsuwan Atom.