This chapter opens with Lieut. Hope and Cleo accosting Dawson, owner of the auction room, standing before his once flourishing business watching the building go up in smoke. As Hope is copying the list of bidders of the books from notes in the hand of Dawson, the auctioneer points out Satsuma to them as one who obtained a copy. Without further delay Satsuma jumps into a waiting taxicab. Hope, Cleo and "hook" follow in another car, tracking him to the home of Stephansky, a bomb maker. Meanwhile, Olga, the Russian spy, and Gerald Morton, who, like her, seeks the secret of the submarine, are speeding toward Stephansky's home. Satsuma manages to get throught the traffic jam while Hope and Cleo are halted by the policeman. However, through "Hook's" strategy, they manage to get away. Olga's intoxicated driver, turning a corner, plunges his machine into the car in which Morton is a passenger. The occupants face each other. Hope and Cleo manage to get away from the traffic policeman. When Satsuma arrives at Stephansky's, he sees Olga and Morton entering. He hides in the shrubbery. Hope and Cleo drive up in a few minutes. Morton sees them through a window. Olga recognizes Stephansky as one of her aides and exchanges signals with him. Morton, begging to be hidden, confesses to Olga he is after the secret and - the girl. She secretes him and instructs Stephansky so that when Hope and Cleo knock at the door she is told to return alone that night. She goes alone to the house and is immediately seized and efforts made to make her reveal the secret of the submarine. Morton and Olga, having perused the books purchased by Stephansky, have failed to find the secret therein. They believe Cleo knows, so Morton, masked, enters the room, and he and Stephansky bind Cleo, place her in a cellar and tell her she will remain captive until she discloses the secret. Hope and "Hook" go to Stephansky's. The lights are extinguished and the lieutenant, his suspicions now confirmed, breaks in the door. Stephansky leaps upon Hope and Morton seizes a bomb. Stephansky grasps Morton's wrist. The bomb falls through the secret door in the floor and into the cellar where Cleo lies bound. There is a terrific explosion and the house is blown up. Moving Picture World, June 1916
See Episode One for cast listing.