Gregory employs a cunning strategy to convince his wife that she is going mad, hoping to have her institutionalized, giving him power of attorney over her and allowing him to search unabated for the jewels. The plan almost works. Paula is saved by something that happened during her trip to the Tower of London, as it also resulted in a chance encounter with Inspector Brian Cameron of Scotland Yard (Joseph Cotten), an admirer of Alice Alquist since childhood. Seeing Paula, who looks very much like her aunt, rekindles Cameron's interest in the cold case murder of Alice and her jewels, a royal gift, that had never been found. With the aid of a police patrolman, Cameron figures out that Gregory slips into a vacant house next door and enters his own attic via a skylight. Cameron eventually gets inside the house to see Paula and confirms that the gaslights are indeed flickering, and they discover the letter from Bauer that Gregory had told her was a figment of her imagination.