****SPOILERS*** It's with all the brain power packed into this super computer, nicknamed "The Brain", developed by Madison Electronics NASA expects to use it in the space program to get us, That's the USA, to the moon before the Soviet Union. It just happens that this Chicago criminal organization lead by "The Brains' of the outfit Patrick, Howard Petrie, plan to kidnap or brain-nap "the Brain" and hold it hostage until they get $300,000.00 from the president of the company Russell Madison, Vinton Hayworth, or else sell it to the highest bidder ,namely the "Evil Empire" Soviet Union, instead.
With the Chicago Police lead by the brainy and tough head of M Squad Let. Det. Frank Ballinger, Lee Marvin,put on the case to rescue "The Brain" they check out all the wear-houses in Chicago that are big enough to store "The Brain" in secret without being noticed. Using modern, in 1960, eavesdropping technology it's later discovered that "The Brain" is hidden away in this deserted wear-house just a block away from the Madison Electronics building that it was stolen from!
***SPOILERS*** Ballinger going undercover as the man in between, the police and brain nappers, rigs this suitcase up with a listening device that will tell the police just where "The Brain" is being stored. Also in the suitcase is the $300,000.00, all marked bills, that's to be paid to get "The Brain" back to its rightful owner Masison Electronics. It takes more guts then brains for Let. Det. Ballinger to pull all this off faking that the suitcase fulled with cash has an explosive device attached to it that only he can disarm. With time running out a gun pointed to his head Ballinger plays it real cool as Patrick and his boys start getting suspicious in the BS story, the explosive device that only he knows how to disarm, as he holds them off until the entire Chicago police department comes crashing and piling into the wear-house.
With "The Brain" now after the successful police raid in friendly hands, the US Government, the possibility of the USA reaching the moon before the Soviets is a forgone conclusion thanks to the heroics efforts of the Chicago PD and of course M Squad's own Let. Det "Fearless Frank" Ballinger!