***SPOILERS*** Free-lance photographer Mike Kovac, Charles Bronson, uses his photographic skills to entrap hoodlum and mobbed up nightclub owner Larry Gaines, Johnny Seven, together with his girlfriend Carla Norris, Dolores Donlon,in the brutal murder of Gaines' accountant Phil Mason, Don Dillaway.
It was Mason's threats to go to the D.A in him going straight after years of him cooking Gaines' books in the nightclub, a front for mob activity, he owns that cost him his life. Mason being gunned down by Gaines with the witnesses to Mason's murder suddenly developing a case of amnesia had Gaines walk with the D.A having nothing to hold him on. It was the late Phil Mason's old lady, Janne Bates, who went to Kovac for help in getting the goods on Gaines that would eventually send him to the electric chair for the murder of her husband!
Using his camera as a weapon Kovac secretly photographs Gaines in a number of compromising positions, with beautiful dames at his nightclub, and used those photos to get his girlfriend Carla, in her feeling that he's two-timing her, to testify against him in Mason's murder that she was an eye witness to. Gaines trying to get back at Kovac tries to get him to get into a boxing match with him in order, in Gaines being the US Army middleweight camp in Germany, to whip his behind which sadly backfires on him! Kovac after taking a few cream-puff jabs from the ""Champ" flattens Gaines with a one two combination without as much as him breaking into a sweat.
***SPOILERS**** It was when Kovac later photographs Carla together with a number of young and handsome men that he set her up with that Gaines, whom Kovac sent the photos to, lost it! An outraged Gaines in trying to work the innocent Carla over for "cheating" on him had her finally spill the beans on Gaines and implicate him in Mason's murder! Something the the local police and District Attorney's Office with all the resources at their disposal couldn't!