SUSPICION

A quiet, unnerving customer comes into the bar, and drives everyone crazy as they try to figure out what he's up to. They suspect a paternity suit against Sam, an IRS audit of Norm, and a postal investigation of Cliff. But it turns out just to be a friend of Diane's, whom she asked to come to Cheers so she could study how the gang reacted. They warn her that ``We don't get mad...''. So when she has an opportunity to go on TV, she mistakenly thinks it's their ruse to get back at her.