A highly insured Shakespeare First Folio is stolen from London University, and Robin Scott arrives to investigate. First Robin gets a list of possible buyers of the folio, and eliminates all but one, an unscrupulous collector named Haldane. Then from the university librarian, Wilkins, Robin learns that a shady character named Begstone must be the man behind the theft. To get the suspected buyer and seller together where he can observe them, Robin tricks Begstone and Haldane into a meeting. It is apparent that there was a deal between the two men, but now Haldane suspects Begstone of holding out on him. By pretending that he has the folio, Robin lures Haldane into breaking into his hotel room. During his grilling of Haldane, Robin suddenly realizes that only one man could possibly have the missing folio--Wilkins, the librarian. But when Robin gets to Wilkins, the man has been beaten up. He confesses that he did steal the folio, but now Begstone has it. In an exciting climax Robin crashes in on Begstone and Haldane, cleans up, and at last recovers the missing folio.