The police are in pursuit of a man who can change into gas and who is using that ability to rob banks so that he can pay for a recital by a dancer with whom he is in love. The film is an imaginative thriller from Toho, directed by Ishiro Honda and with effects by Eiji Tsuburaya. The third act, in which the police set a trap for 'the gas man', seems a bit weak - surely the titular character would have suspected a trap when he is the only person at the recital; however, I was watching a subtitled version and might have missed something (perhaps 'the gas man's' behaviour was in keeping with his obsession with the dancer). The special effects are simple but effective, and overall, the film is an entertaining example of Toho's early 1960's non-Kaiju tokusatsu (although not as good as 1958's "The H-man").