The penniless 19th Earl of Locharne, the owner of a run-down Scottish castle which he has made into a mostly empty hotel, has to deal with a myriad of financial troubles, starting with his creditors and the few disgruntled tenants. Then there is Mr. Phillips, a socialist official from the British National Coal Board, which wants to requisition it to convert into a vacation hostel for miners and their families. The earl introduces Phillips to a beautiful family ghost, Ermyntrude, the earl's grandfather's mistress. Next, a long-time prospective purchaser, wealthy, attractive American divorcee Mrs. Clodfelter Dunne, shows up unannounced to look over the place in person. The earl's evident attraction to Mrs. Dunne is observed with dismay by his assistant, "Boss" Trent. Both Mr. Phillips and Mrs. Dunne stay overnight at the castle. The earl is hard-pressed to simultaneously convince the former that the castle is falling into ruin and the latter that it is well worth purchasing. Meanwhile, eccentric boarder Miss Nicholson is obsessed with proving that the earl is actually the rightful King of Scotland. When Mrs. Dunne expresses her belief that she is a member of the family, a delighted Miss Nicholson sets out to try to trace her lineage. Mrs. Dunne eventually decides to purchase the place. She and the earl drive to Aberdeen to see his solicitor, Pettigrew. The price is $250,000. Later, the earl receives a message to see an unnamed lady in hotel room 57. However, when he enters the room, he is disappointed to find Miss Nicholson and her followers, bent on a Jacobite restoration. The ensuing party runs late into the night, with Mrs. Dunne and Pettigrew in attendance. The earl and Mrs. Dunne, both rather intoxicated, return to the castle around four in the morning. The next day, Trent, believing that the earl and Mrs. Dunne were alone in the hotel room, quarrels with the earl. She makes him inform Mrs. Dunne that the castle is in danger of being requisitioned. Mrs. Dunne takes back her cheque. However, after hearing from Phillips that he has been passed over for promotion, the earl has Mrs. Dunne offer him the position of managing the castle for her for a large salary, provided he turn in a recommendation that the castle not be acquired. He agrees. Now that the sale has been reinstated, the earl asks Trent to marry him, much to her delight. Miss Nicholson interrupts them with dreadful news: it turns out the earl is not in the direct line of succession after all.
At the time of its American release, The New York Times described the film as a "slender but thoroughly good-natured little British comedy" In the 21st century, a reviewer on the website Fantastic Movie Musings and Ramblings wrote, "all in all, a delightful comedy." A reviewer for TVGuide.com said, "this stage play should have stayed on the stage."
