***SPOILERS**** It's when the nutty multi millionaire and pillar of the community Wills Stone, Ian Wolf, ends up getting himself locked up in the safe of his own bank that drastic matters had to be taken to get Stone out before, with the air in the vault being exhausted, he suffocates to death.
With time running out in not being able to crack open the bank vault it's decided to get jailed master safe cracker Eddie Carew known as "The Human Can Opener", Dean Jones, to get the Job done. Eddie who's been undergoing therapy to overcome his compulsion to crack safes is now given the task to do exactly that. Thus making all the help he got from his prison psychiatrist Dr. Falery, Harry Townes, go straight down the drain! With a pardon from the governor withing for him if he saves Stone's life Eddie has no choice but to do the kind of job that he's been trying to avoid all these years behind bars. There's also the fact that Edde'girlfriend Sally,Shellah Walls, who's been withing for him all the time he's behind bars wants him to do the safe cracking that he decides to finally do it but with one condition: Have his friend Pinky Ferguson, Stanely Adams, the human blowtorch give him a hand with it!
As Dr.Falery feared Eddie by being given a chance to crack open safes again resorted back to his criminal past. In not only planning to crack open the safe and save Stone's life but check out, together with Pinky, with the hundreds of thousands in cash locked inside in it! Even if it jeopardizes his governor's pardon and being with the girl Sally who's withing for him on the outside!
***SPOILERS*** It's in fact Sally who gets Eddie to change his mind and finally go straight after he and Pinky took off during all the confusion,in a police squad car, with the cash! Sally did that even if she had to lock herself up in the bank vault and put her life on the line,in suffocating to death,to get Eddie to come back and turn himself in in order for him to save her life! In the end it was Eddie who in fact got the last laugh with his prison Warden Dewitt, Alan Hewitt, who's been giving him such a hard time all throughout the movie. Dewitt also accidentally locked himself in the vault with Eddie now guaranteed a pardon, despite his momentary laps of being a law abiding citizen, the only one who can open it. And he took his sweet time to get the job done. Making Warden Dewitt feel as helpless as the many convicts, like Eddie Carew, in the prison that he's in charge of.