***SPOILERS*** Far out yet down to earth sci-fi thriller about a number of mindless atomic zombies being used by a vengeful gangster to get even with those who had him deported into exile in Italy. Gangster Frank Buchanan getting involved with ex-Nazi scientist Dr. Wihelm Steigg has him create a number of zombies from corpses, that he stole from the local city morgue, to go out and kill those who had him sent away.
By rejuvenating their dead brains cells with high doses of atomic energy Dr. Steigg is able to make the dead rise again as their sent out to kill those whom Buchanan commands them too. Leaving a trail of radiation in their wake the zombies ,like the sparrows flying back to Capistrano, go back to where they came from their base in Dr. Steigg's laboratory. Buchanan, who's illegally and happily back in the USA, conducts his zombie search and destroy operations out of Dr. Steigg's secret hideout outside the city via a TV monitor that receives transmissions from the Zombies brains.
With the murder of hoodlum boss Hennessy and D.A MacGraw a patten is discovered, by police lab supervisor Dr. Chet Walker, in their deaths. Both were involved in putting Buchanan behind bars and on a boat out of the country. It's now becomes apparent to Dr. Walker that former Buchanan Gang members Dunn & Banning, who gave evidence against him at his deportation trial, are the next to be knocked off and are given a round the clock police protection.
With police Captain Dave Harris kidnapped killed and mind controlled by Buchanan and Dr. Steigg he's then sent back to his police station to finish off both gangsters Dunn & Banning, who are there in protective custody, in order to get his revenge on the whole lot: Hennessey MacGraw Dunn & Banning.
By now Dr. Steigg is scared stiff that Buchanan's mad actions will lead the police to his hideout and wants to call it quits. Only to have the gangster kill him and take over the control of the atomic zombies. It's the mine controlled Capt. Harris who leads the police Army Marines and Air Force back to Dr. Steigg's and Buchanan's hideout as Buchanan sends them, his gang of atomic zombies, out to do battle with the US Armed forces. Winning the first round against the US Army the zombies also start causing havoc all over the state with them, by using their atomic brains, having planes fall from the skies trains derail and cars and trucks lose control on the highways and slam into each other.
Just when it looked like curtains for the US Army and local police with the zombies, and Buchanan, about to take over its then when the mind numbed and brain dead Capt. Harris comes back to life. Breaking into Dr. Steigg and Buchanan's laboratory Capt. Harris nukes Buchanan, with a blast of atomic energy, and destroyed the machinery that controls the rampaging zombies causing them to drop harmlessly like flies.
Captain Harris is the big hero in this film even though he never knows it with his brain in limbo only being, for a time, able to take orders from Buchanan. Harris somehow seemed to be able to get it all together in the end realizing, if only by instinct, that by following Buchanan's orders he was doing himself as well as his country, the USA, serious harm. You can't say that Captain Harris gave his life for his country in being destroyed together along with Buchanan and Dr. Steigg's zombie-control machinery since he was already dead. But at least he made his brief yet explosive stay on earth, as a living dead man, a rewarding one in putting an end to the evil Buchanan/Steigg atomic zombie menace.
