After spending years in prison, a top safe-cracker owns a couple of businesses, which are fronts for diamond heists. After his trusted fence is killed, he agrees to work with a powerful mobster, but to dire consequences.
 
Don't know if you want to crack this safe.
 
FUN FACT:  After The Godfather (1972), this was James Caan's favorite film of his own. He had stated that his monologue in the diner was the scene of which he was most proud in his career.