An ambitious reporter, investigating a senator’s assassination, realizes witnesses to the shooting are systematically dying and discovers a multi-million dollar corporation which serves as a front for the recruitment of political assassins.

Dexter Riley is a science student at Medfield College who inadvertently invents a liquid capable of rendering objects and people invisible. Before Dexter and his friends, Debbie and Richard Schuyler, can even enjoy their spectacular discovery, corrupt businessman A.J. Arno plots to get his greedy hands on it. Slapstick hijinks ensue as Dexter and his pals try to thwart the evil Arno before he can use the invisibility spray to rob a bank.

Peter Ustinov stars as the eponymous wraith, who returns to Earth to aid his descendant, elderly Elsa Lanchester (Stowecroft). The villains want to kick Lanchester and her friends out of their group home so that they can build a crooked casino. Good guy Steve Walker (Jones) gets caught in the middle of the squabble after evoking Blackbeard’s ghost.

The Louisiana wedding of debutante Phoebe Ann Naylor to Don Andrea de Baldasar, El Duce de la Casala is stopped by the Cavalry over a matter of honor. Don Andrea flees across the river to Texas, where he meets up with Sam Hollis and his Indian sidekick, Kronk, who are carrying rifles to the town of Moccasin Flats. Don Andrea rescues an Indian maiden, Lonetta, tames some longhorns, competes with Sam for Phoebe’s affections, eludes a Comanche war party and the cavalry (who have come to Moccasin Flats to celebrate Texas’ statehood) and ultimately saves the town and gets his girl.