Formula For 654

Dr. Petrie describes to Nayland Smith what it's like to experience 'The Purple Death'. Meanwhile, Fu Manchu is smoking opium when Florette shows up and gets stuck in the lab with Paul Sterling. After Sterling and Petrie find out that Petrie is still alive and being held prisoner by Fu Manchu, the two men try to break out of the lab. During their escape attempt, they run into Nayland Smith. The three of them come up with a plan to get away from Fu Manchu's hideout and make sure the police catch him.