A British operative vanishes while transporting a confidential file to Washington, prompting His Majesty's government to enlist "Holmes" (Basil Rathbone) and "Watson" (Nigel Bruce). Following a close call at the missing man’s residence, they decide that traveling to America is essential for progress in their inquiry. “Watson,” naturally, is thrilled about the trip, which allows for some sightseeing—a glimpse of the S…