Quantum Leap S01E05 - Double Identity - November 9, 1965

Though his goal as a Mafia hitman named Frankie is unclear, Sam follows a list of instructions, supplied by Ziggy in an effort to bring Sam back to the Project. These instructions result in the Great East Coast Blackout and, rather than leaping home, Sam finds himself in the life of the Mafia don who's been jealously preventing a romance between Frankie and the don's girlfriend. Sam believes he knows his mission, and publicly announces Frankie's marriage to the girlfriend, putting himself in a position to call a winning Bingo number.