The action starts on the night of the day on which the “Crack o’ Doom” ends. In the dark Judith and Marrophat smuggle Rose into Trine’s house in New York from their car. Leaving Rose with Marrophat, Judith reports to her father, who sends for Rose. Although worried over Alan, Rose is defiant towards her father. At a taunt from Judith, however. Rose is accused of loving Alan. Trine orders Judith from the room and questions Rose. When he tells her that Alan has been assassinated, she tries to disbelieve but finally breaks down and is led, a weeping prisoner, to her room a hundred feet above the street. Marrophat tries to make love to Judith. She ignores him and he secretly vows vengeance. Marrophat tells Trine how Judith prevented Alan’s death at the bridge. Judith accused Marrophat of lying because she refused his advances. Trine received an unsigned note reading: “Digby has reserved suite at Monolith Hotel to be held for Arthur Lawrence.” Judith departs in anger and Marrophat tells of Judith’s love for Alan. Tipping the head bellboy at the Monolith. Marrophat gives him a trey of hearts, indicating a practical joke. As they talk, Alan enters and registers as Arthur Lawrence. After he has entered the elevator, Marrophat leaves hurriedly for an East Side dive, where he pays Red November to assassinate Alan. From his room Alan phones Digby. Unseen, the bellboy slips the trey of hearts into the stationery and leaves. While Trine is apparently sleeping. Judith creeps into the room and reads the note, but as she leaves the room, Trine rouses and traps Judith, proving her disloyalty. Alan slips out a side door unobserved, he thinks. Marrophat sees him and orders Red November to follow his taxi in another, Alan changes taxis several times, but fails to lose November. Believing himself safe Alan arrives at Trine’s house. By bribing a night watchman, he climbs to the girder of an unfinished apartment house across the street and using a flash-lamp and the Morse code communicates with Rose. Judith from her window reads the message, telling Rose to be ready to leave the house by six the next morning. Alan turns and finds November edging along the girder, a knife between his teeth. After a desperate fight, Alan gains mastery, but as Red is slipping over the edge of the girder, Alan grasps him and pulls him back onto the girder, where he collapses, sick with fright. After signaling Rose “good night” Alan climbs to the street. Judith plans to outwit Rose and Alan, and enters Rose’s room where she empties vial of poison into a glass and at the point of a gun forces Rose to submit a deal of the cards to decide which shall drink it. Judith draws the trey of hearts and loses. Rose faints as Judith starts to drink. Judith, however, throws the glass aside and dresses in Rose’s clothes. Meantime Alan enters the building opposite, bribes the ironworkers and they prepare a steam crane for his use. With one foot in the iron hook, he is swung to Rose’s window, where he takes Judith from the window, thinking it is Rose, and they are lowered to the street. At this moment, Marrophat, seeing Alan being lowered to Rose’s room, rushes through the halls and bursts into the room, but is too late. He mistakes Rose for Judith, until, as she comes from her faint, her words show him his error. When he learns that Judith is going to marry Alan instead of Rose, he rushes out in time to see the machine disappearing. Calling a taxi, he starts madly in pursuit.