The lonesome daily routine of a top-notch Security Chief of a London auction-house, who's a bit nerdy and unstable and so completely obsessed with his work that he even spies on his neighbors from his home seeing it not as an invasion of privacy but as the natural extension of his job, is interrupted when a scared female neighbor rings his doorbell to complain of a ski-masked stalker. He helps her secure her apartment and falls for her, but she rejects his advances. Meanwhile, the auction-house handles a valuable Renaissance collection which includes a necklace said to bear a deadly curse. It belonged to a medieval nobleman who was betrayed by his wife and killed by her lover, a member of the notorious medieval Corvini assassin family. The jewelry supposedly continued to bring only betrayal, murder and madness to those who later owned it.