House of Games1

Margaret Ford (Crouse) is a psychiatrist. She has published a book, Driven: Compulsion and Obsession in Everyday Life, which has made her financially well-off. One day, she's in a session with Billy, a compulsive gambler who informs her that his life is in danger. He owes $25,000 to a criminal figure — money he doesn't have — and if he doesn't pay, he will be killed.
Margaret visits a pool hall and bar called the House of Games and confronts the man Billy owes, Mike (Mantegna). After a brief conversation, Margaret sizes Mike up as a tough talker, but not a violent gangster. Mike reveals that Billy's debt is only eight hundred dollars and agrees to forgive the debt if Margaret accompanies him to a high-stakes poker game as his girlfriend, using her to help spot the tell of another gambler (Jay).
Exhilarated at the chance to take part, Margaret even volunteers $6,000 of her own money to back up Mike's bet because she’s spotted the tell that Mike’s opponent is bluffing. Things go wrong. Not only does the player have a winning hand, he also brandishes a gun, demanding the $6,000 she promised as collateral. It is only when Margaret sees a drop of water fall from the pistol barrel that she realizes the whole setup is a con – designed strictly to take her money. Mike and his men see that the jig is up, and nonchalantly pack up the con. Mike apologizes, saying it was “only business … nothing personal.”