Mission: Impossible (1966) : 3x15

A gangster, Constantine Victor (aka ""Mr. V"") has had the last witness against him on a murder indictment killed. Johnny Costa, Victor's associates and a casino owner, is the only one with enough evidence to get Victor convicted. The IMF must con Costa into talking. Phelps as a syndicate killer warns Costa that someone has put a contract on him. Cinnamon charms Costa and has him endorse minor credit slips which the IMF then forges for bigger ones. Rollin is a bookkeeper who supposedly works for Costa, finds an unlisted $25,000 planted by Barney, and the fake credit slips. Thanks to a prerecorded call from ""Victor"" mimiced by Rollin, Costa is relieved of duties. Costa confronts Cinnamon and gets her to admit she is working for Victor. Fleeing from Willy as another hit man, Costa locks himself in the casino vault to protect himself until he can testify against Victor.