Modelled on the real-life story of Arthur "Doc" Barker and his mother Kate “Ma” Barker, matriarch of a brood of criminals during the Depression era, it follows Jarrett and his gang as they rob a train and hide out in a mountain retreat in the High Sierras. Eventually they are caught but the wily Jarrett confesses to a hotel payroll robbery that took place at the same time as the train heist and so only gets a two year sentence. The police plant an undercover agent, Vic Pardo (Edmond O'Brien) in his cell, however, and when Jarrett breaks out after the death of his mother, Pardo gets taken along. Jarrett firstly sorts out one of his gang (Steve Cochran) who has taken up with his wife (Virginia Mayo) then he sets about organizing a big payroll heist at an oil refinery where the film’s classic closing scene takes place.
Cagney is the focal point of the film in an outstanding portrayal of what is an interestingly written character in a film that is notable for the uncompromising way in which it treats its subject matter – the criminal underworld. Often this sort of thing is balanced by some kind of domestic sub-plot involving the police side of the equation in a good guys/bad guys contrast but bar a brief allusion to O'Brien's intention to "go fishin'" there is no let up here for pursuer or pursued and it is this dynamic which makes the film still so entertaining today.
Given the essentially socio- and psychopathic energy which drives Jarrett, his demise is a suitably over-the-top one and the grand finale with Cagney yelling "We made it, Ma - top of the world" as the globe-shaped gas container blows him to Kingdom Come is one of the genre's legendary moments. There are some small aspects which niggle, such as the too facile way in which Jarrett drops his suspicion of O'Brien’s brown-nosing and the way in which the latter converts a mantel radio into a tracking device and so snares his prize, but Cagney's searing performance sweeps all before it.