Mission: Impossible - Season 1 Episode 27 : The Traitor 1973

An American intelligence officer, Hughes, has defected to the enemy with the only copy of an encoded top-secret message. The IMF must get to him, get him out, discredit him, and recover the message before the enemy can get a cryptographer, Belson, to work on the message. Rollin takes Belson's place, and sets it up so that Ambassador Brazneck, in charge of Hughes, believes that Dan is going to buy the papers from someone in the embassy. Rollin-as-Belson works with Hughes to decode the message, then drugs him. Willy gets special agent Tina Mera, a contortionist and acrobat, into the embassy through a fake air duct. She uses a fake bed covering to make Hughes ""disappear"", then break into the vault and get the real message. With Hughes out, Briggs picks up the fake message from someone pretending to be Hughes, who has ""disappeared"" from the embassy. Tina returns, plants money on Hughes, and removes the fake disappearing bed cover. Brazneck believes Hughes has betrayed him and Hughes flees