Dexter Riley can be really a science student at Medfield College who invents a capable of earning people and objects imperceptible. Before Dexter and his buddies, Debbie and Richard Schuyler, can also enjoy their spectacular discovery, corrupt businessman A.J. Arno approaches to receive his greedy hands on this. Slapstick hijinks ensue as Dexter and his pals attempt to thwart the wicked Arno until he can utilize the invisibility squirt to rob a bank.