One year after The Alienist, with Sara Howard, now a private detective, seeking out Dr Kreizler's help in finding the kidnapped infant daughter of a visiting Spanish dignitary. Dr Kreizler reunites with Sara, John Moore...
The discovery of the mutilated corpse of a boy prostitute leads a psychologist to link the crime to the earlier murder of a child patient. He enlists the help of his college friend, a newspaper illustrator, to gather evidence in the case.
Kreizler looks for other victims of the serial killer. Sara brings in a vital clue. Kreizler treats Sara, Moore, Marcus and Lucius to Delmonico's and informs them they will be teaming up to catch the killer.
The team set a trap to catch the killer. Moore visits a friend. Kreizler is filled with self-doubt over the investigation. Roosevelt is part of an event with the city elite. Sara looks into Kreizler's past.
Kreizler and Moore follow a new lead. Sara visits a hospital which forces her to confront her past. Cyrus recovers from his injuries. Byrnes and Conner are plotting against the team. Marcus and Lucius follow a clue.