The Princess Comes Across (1936 William K Howard)

Lombard is pretending to be a Swedish princess (cuing amusing acting / accent) on transatlantic liner; MacMurray is adjacent passenger - a concertina player, no less. (Whoever's actually playing that concertina is damn good.) Also on board is a murderer, a blackmailer and an international troupe of detectives, memorably including Misha Auer and Sig Rumann. So it's a merry pot.

How can it be adapted from a novel (Louis Lucien Rogger) and 'based on a story by' (Philip MacDonald)? But it is. Screenplay: Walter DeLeon, Francis Martin, Don Hartman (Road films, director of A Holiday Affair) & Frank Butler.  Shot at Paramount by Ted Tetzlaff.

With Douglass Dumbrille, Alison Skipworth, The Man Who Came to Dinner's George Barbier, William Frawley, Porter Hall (Sullivan's Travels), Lumsden Hare, Bradley Page & Tetu Komai.