Thackery enlists Edwards to help him test a new hypothesis. After rejecting Robertson's advances at The Knick, Lucy learns that confession isn't always good for the soul. Young journalist Genevieve Everidge works on a story about one of Thackery's rivals. Cornelia is dismayed by the limits of her husband's (Tom Lipinksi) sympathies; Barrow faces a new adversary at Tammany Hall; Gallinger is intrigued by a discussion of eugenics at a class reunion; Edwards deals with a surprise visitor.

A subway explosion leads to an influx of patients at The Knick, but little margin for profit. Pursued by Henry, Lucy takes to heart advice from one of Ping Wu's girls. An addict's misfortune gives Thackery an ideal test case for his latest theory on addiction. Bertie submits his adrenalin research to Zinberg ; Cornelia gets a new clue in Speight's death; Barrow repays a debt but gets no credit; Genevieve charms the Chickerings; Harriet finds herself a boarding-house pariah.