Kreizler and Sara discuss the capacity to kill. Moore goes on a date. Byrnes and Captain Connor keep an eye on a potential suspect. Roosevelt finds himself under public scrutiny.

The team learns more about the killer. Moore and Sara share an intimate moment. Kreizler seeks advice from an old mentor. Roosevelt takes action.

All is not what it seems at the Lying-In Hospital as Sara persuades a young nurse to disclose what happens behind closed doors. Kreizler is convinced that hypnosis might unlock the traumatic memories of Senora Linares.

The clock is ticking for the team to locate baby Ana. Sara worries about her young undercover detective Bitsy Sussman. William Randolph Hearst hosts a lavish ball celebrating his goddaughter Violet's engagement to Moore.

Sara, Kreizler and Moore travel to Brooklyn in search of clues. Byrnes plans to double-cross the team as the killer's behavior becomes unhinged. Sara and Moore's feelings for each other force them to confront difficult choices.

While Sara, Moore and Kreizler struggle with decisions about their future paths, New York is in the grips of an all-out manhunt for the killer, and the team must overcome the wrath of the police and an underworld gang on the rampage.