The Brothers Brannagan - Season 1 Episode 5 Duet

Diane hires Mike Brannagan to guard her sister while she tries to buy off a man who wants to marry her. Diane tells Mike that Kate is embezzling her money which is why she doesn't want her to marry. Then by a neat trick Diane locks Mike in a room. She gets to a telephone and informs her fiance where Kate and Mike are keeping her and that Mike is unarmed. She tells Mike that when her fiance arrives, he will kill Mike and their story will be that Mike was attacking her.