Tough narcotics detective ‘Popeye’ Doyle is in hot pursuit of a suave French drug dealer who may be the key to a huge heroin-smuggling operation.

Don Gregor, the son of famous plastic surgeon Dr. Boris Gregor, begins to hang around with young criminal Vic Brady and carry a gun. The pair attempt an armed holdup, and when things start to go wrong Gregor accidentally kills a night watchman. Fearing that Gregor plans to turn himself in, Brady kills him and blackmails Dr. Gregor into giving him a new face.

For the ventriloquist Gabbo his wooden dummy Otto is the only means of expression. When he starts relying more and more on Otto, he starts going mad.