Writer William Magee accepts a wager that he can finish writing a book in 24 hours, and travels to the deserted inn Baldpate, a summer resort now in the midst of winter, including a blizzard, to finish his opus. Told his is the only key, Magee is interrupted numerous times in the first hours by a parade of characters who appear to be in search of $200,000 meant as a bribe for a local politician, and who all seem to have an only key. As the situations become as outlandish as any he could concoct for his novel, Magee lets his infatuation with one of the "guests" get in the way of writing and solving the plot behind all that's happening at Baldpate.