A group of eight college friends gather together at an island mansion belonging to heiress Muffy St. John to celebrate their final year of school. They soon discover that each has a hidden secret from their past which is revealed, and soon after, they turn up dead. But are they really dead, or is it a series of very real, very cruel April Fool's jokes? The hostess, Muffy, seems to be the only one who is going on. Could she be the killer?