Mission: Impossible - Season 1 Episode 17 : The Frame 1973

Gangster Jack Wellman is moving syndicated crime into politics, killing off certain politicians and replacing them with men more sympathetic to the Syndicate. The team goes in as caterers. Cinnamon sneaks into Wellman's room, blows a hole in the wall, and inserts a fake safe. Meanwhile, Barney and Willy break into the real vault from the rear and steal the 4 million in profits that Wellman has tucked away, and which he is to split with his fellow mobsters at a dinner that night. They open the real vault and discover the money missing. Going upstairs, they find Cinnamon who claims to be Wellman's girlfriend, tells him she knew ""it"" wouldn't work, and reveals the fake safe. As Cinnamon and the rest of the team depart, the other mobsters tell Wellman to open the safe or they'll kill him, and don't believe his desperate pleas that he's never seen that safe before in his life.