Twenty years ago, old Mrs       Barlow was killed in her home at 12, Pimlico Square for her priceless rubies       The murderer searched the whole house without finding them, then disappeared       The house has been empty since then, but now Paul and Bella Mallen move into the apartment       Bella Mallen suffers from forgetfulness and nervousness - at least that is what her husband tells her       An elderly horse wrangler, B      G       Rough worked as a policeman twenty years ago and still remembers the unsolved case       He notices that Mr       Mallen looks just like Louis Barre, Mrs       Barlow's nephew       And why does Mr       Mallen so mysteriously leave every night just to go into the apartment next door, nr       14