底本：江戸川乱歩全集　第1巻　屋根裏の散歩者 (光文社文庫) 光文社

A thief is on the loose in Tokyo, a smash and grab artist that targets high-end jewelry stores. The identity of this burglar is no mystery. It's a metal robot, dubbed the "Bronze Devil" by the press. Except with its almost magical ability to appear and disappear out of nowhere, the police are powerless to stop one theft after the other. That can only mean it's time to put master sleuth Kogoro Akechi and the Boy Detectives Club on the case.

The year is 1953. The Korean War is winding down. The Cold War is heating up. The United States detonated the first hydrogen bomb the year before. Godzilla will make his debut a year later. UFOs are appearing all over the world. And in Ranpo Edogawa's latest novel, five flying saucers zoom across the skies of Tokyo. A day after that incident, a woodsman stumbles out of the forest to report the landing of an alien spacecraft in the mountains southwest of Tokyo. A month later, Ichiro Hirano's next-door neighbor goes missing. And then reappears as abruptly as he vanished, claiming was kidnapped by a lizard creature from outer space. That same lizard creature is now stalking the pretty and talented sister of Ichiro's best friend. What in the world is going on? What do the aliens want? And where did they come from? These are the kind of questions that only master sleuth Kogoro Akechi and the Boy Detectives Club can hope to answer.