Mister 880 (1950)

A Secret Service agent charged with investigating small-time counterfeiter Mister 880, Steve Buchanan (Burt Lancaster), arrives in New York with his partner, Mac (Millard Mitchell). Befriending several locals, including the pretty Ann Winslow (Dorothy McGuire) and jolly old "Skipper" Miller (Edmund Gwenn), Buchanan begins investigating the trail of counterfeit money. When the trail leads back to those he's come to know in New York, Buchanan must balance his duty with his new relationships.