Lizzie Borden High's class of '72 are going through the motions at their tenth-year reunion, until deranged alum Walter Baylor, driven insane by a sadistic senior-year prank, escapes from the mental institution and crashes the party. When guests start getting bumped off, the other alumni, including snooty yacht salesman Bob Spinnaker, class tease Bunny Packard, and class zero Gary Nash, spring into action to uncover the culprit.

In this send-up of the Humphrey Bogart detective films of the 1940s, a man idolizes Bogart so much that he has his features altered to look exactly like him and then opens up a detective agency under the name Sam Marlow.

Camp Sasquatch will be bought out and closed unless owner Coach Giddy wins the boxing competition scheduled for the end of the summer. Tough city punk Flash, who's performing his community service time at the camp, is the coach's best hope. Flash reluctantly offers to help and so must use his raw sparring talents to get a motley group of adolescent misfits into fighting shape, while also trying to win the heart of pretty Cheryl.