A subway explosion sends a flood of patients to the Knick; while being pursued by Henry, Lucy heeds advice from one of Ping Wu's girls. Later, a troubled addict makes an ideal test case for Thackery's theory on addiction; Bertie submits his adrenalin findings to Zinberg; Cornelia uncovers a clue about Speight's death; Barrow pays off a debt; Genevieve charms the Chickerings; and Harriet becomes a boardinghouse pariah.