Previously filmed in 1917 and 1925, the evergreen George M. Cohan-Earl Derr Biggers stage mystery Seven Keys to Baldpate was remade as a talkie in late 1929 (and there were still three more remakes to come). Richard Dix stars as novelist William Magee, who's having trouble completing his latest manuscript. Promising his agent (Crauford Kent) that he'll finish the book within 24 hours if only he gets some peace and quiet, Magee heads off to the Baldpate Inn -- for which he thinks he holds the only key. Unfortunately, the mildewed old inn turns into a hotbed of intrigue as several mysterious characters, all bearing duplicate keys, intrude upon Magee's solitude in search of $200,000 in stolen bonds. In the course of the long, long night, a woman is seemingly murdered and a crooked sheriff lays claim to the money himself before Magee takes a hand in matters -- and then, the owner of the seventh key to Baldpate shows up. Even after repeated viewings, the film's double surprise ending holds up beautifully. Beyond bringing a classic theatrical piece to the talkie screen, Seven Keys to Baldpate served an important technical purpose: RKO Radio Pictures used the film to test out its new repertoire of sound effects, ranging from rolling thunder to realistic gunfire.