[4][1] Herts-Lion International Corp. acquired the Western Hemisphere rights to the film in January 1964 and planned to release it theatrically in the United States.

[5] At an amusement park's "Cave of Horrors" attraction, a man is stabbed to death and the killer leaves behind a gold-plated dog tag, a note asking the victim to meet them there, and a piece of Cryotron transistor wire.

Kirioka, Kobayashi, and Onosaki eventually discover that 14 years prior, Onishi, the victim, intelligence agent Takashi, and Construction Corp. foreman Taki were all soldiers assigned to protect scientist/electrical engineer Dr. Kajuro Nikki's top secret experiments in creating electronic weaponry.

Unbeknownst to Nikki, a bitter Tsudo used the machine to elude the police while seeking revenge on his would-be killers by using the dog tags as a death sentence, sending his victims an audio tape or note detailing his intentions, and stabbing them with a bayonet.

[2] The film has been described retrospectively as "a fast-paced thriller with a sci-fi twist"[6] or "one of the best pure-entertainment science-fiction pictures the studio (Toho) has put out to date.

"[7] Another recent review finds that " It’s got so many weird elements that it’s entertaining, despite a preponderance of scenes of dull people in conservative suits having conferences about the crimes.