- Writers: Jack Amiel, Michael Begler
- Stars: André Holland , Cara Seymour , Charles Aitken , Chris Sullivan , Clive Owen , Eric Johnson , Eve Hewson , Frank Wood , Grainger Hines , Happy Anderson , Jennifer Ferrin , Jeremy Bobb , Juliet Rylance , Leon Addison Brown , Lucas Papaelias , Maya Kazan , Michael Angarano , Perry Yung , Richard James Porter , Suzanne Savoy , Tom Lipinski , Ying Ying Li , Ylfa Edelstein , Zuzanna Szadkowski
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 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.