A high school science teacher is the butt of all his students' jokes, until their bus is hijacked on a school trip. But something more sinister lurks beneath the surface: he's building an atomic bomb in his apartment.

A bad day gets worse for young detective Murakami when a pickpocket steals his gun on a hot, crowded bus. Desperate to right the wrong, he goes undercover, scavenging Tokyo’s sweltering streets for the stray dog whose desperation has led him to a life of crime. With each step, cop and criminal’s lives become more intertwined and the investigation becomes an examination of Murakami’s own dark side.