At school, Louis and Tom are fooling around with Tom's boomerang when Louis flings it in the direction of Ren, Ruby and Monique, nearly hitting them. The group looks for the lost boomerang, but instead of finding it Ren stumbles upon something else. a metal briefcase, the kind used to carry large sums of cash! When the gang gets home, they open it up and check it out. Amazingly, they find that it IS full of money--$4,412 to be exact! Everyone starts mentally dividing up the loot and deciding how they are going to spend it--except for Ren, of course. Though the others are reluctant, they finally listen to Ren when she tells them the money is not theirs and must be turned over to the proper authorities. They all agree that Ren, being the most responsible one, should take the money to the police.
But on the way to the station, Ren sees a pair of lizard-skin pants in the window of an expensive boutique. She stops in to look, and the saleswoman there does quite a sales job on her, so much so that Ren, out of character, spends $4,000 for the pants! At school everyone is complimenting Ren on the pants, but Louis and the others want to know about the possibility of getting the money back in thirty days if no one claims it. Now Ren has to start lying, and she has to deceive even more people when Principal Wexler calls her to his office. There she finds Father O'Neil, who says he's sure he lost the case full of money on the school campus. Ren, as the most trusted student, is expected to help find it. Based on some circumstantial evidence, Wexler accuses Louis of stealing the money and is hauled off and interrogated. Ren lets him take the rap for her.
Ruby and Monique are talking to Tawny, who tells them the pants Ren bought cost $4,000. Now they, and soon everyone else, know that Ren actually spent the money. Everyone confronts Ren in the hall. She manages to get away from them, and a madcap chase ensue, with Ren on a lawn mower followed by pursuers in a golf cart, a motorcycle with sidecar, a bicycle built for two and Louis bringing up the rear on a pony that Beans was given for his birthday. Ren is finally cornered and the moment of truth arrives for her.
But then the rewind button is hit, literally. Ren is back in the boutique, resisting the saleswoman's come-on, and she turns in the money instead of spending it. But the gang does get a reward--they get to keep the case!