A bank heist gone sideways leaves Charley (Walter Matthau) and Harman (Andrew Robinson) scrambling with their stolen money, though not before his wife Nadine (Jacqueline Scott) is killed in the chaos. Believing they’ve covered all traces of their crime, they return to his camper van, only to discover a staggering sum—over $750,000—waiting for them. Charley immediately realizes this isn't ordinary money and that they face a far greater threat from organized crime than from the authorities. His suspicions prove accurate when Boyle (John Vernon) sends his intimidating enforcer Molly (Joe Don Baker) after the cash and to punish those who took it. As Charley desperately tries to get everyone to safety, he must interact with some dangerous individuals to secure passports and other necessities—a series of actions that ultimately jeopardizes their situation. The question becomes whether they can reach safety, money or no money. While I generally enjoy Matthau's comedic performances, he maintains a firm grip on the narrative as Molly demonstrates an increasingly casual and brutal violence toward everyone around him. It’s unusual to see a final scene unfold in a junkyard involving explosives and a crop duster, but director Don Siegel effectively builds suspense leading up to that almost farcical yet exciting ending.

Source on TMDB