Peter Davison stars as bespectacled, aristocratic private detective Albert Campion in this two-part adaptation of Margery Allingham's novel Sweet Danger. On this occasion, Campion endeavors to prove that Britain's Fitton family are the rightful heirs to a Balkan throne. Disguising himself as the king of the monarchy in question, Campion sets about to locate the monarch's missing crown, which of course will verify the Fittons' right to ascension. His search leads to a sinister scheme involving newly discovered oil deposits. In America, "{Sweet Danger" was telecast November 15, 1990, as a single two-hour episode of the PBS anthology Mystery! ~ Hal Erickson, All Movie Guide