October 11, 1864. Detectives Maguire and O’Brien uncover a gang’s scheme to rob some of the wealthiest families in New York City. Corcoran, once informed, must ensure the safety of patrons at an upscale fundraiser without intruding upon Norbert Morehouse and Elizabeth Haverford. As the police prepare for the gala, Maguire reveals a startling, life-changing decision, surprising O’Brien and Corcoran. Meanwhile, Marcus Freeman prepares Jasper Longfield for his exhibition fight against "Irish" Jake McGinnis. As the former boxer trains his new protégé, it becomes apparent to Doctor Matthew Freeman that Marcus has his own interests at heart.

October 18, 1864. Corcoran re-evaluates his decisions about Annie. A group of high society out-of-towners offers Robert Morehouse a unique business opportunity. O’Brien’s wife demands that her husband verifies a rumor that New York City is in danger.

A murder demands Detective Kevin Corcoran work closely with an unlikely partner as General Brendan Donovan is eager to close the case cleanly. Meanwhile, Robert Morehouse makes a difficult decision regarding the trial of Kennedy, leading to a surprising change in the proceedings. With spring on the horizon, the Freemans welcome a loved one back into their arms and home; while Madame Eva Heissen and Ellen Corcoran discover shared secrets they both wrestle to keep hidden.

The greater COPPER family – Uptown and Five Points alike – gather around Detective Kevin Corcoran, who is reeling from a shocking loss. In a quest to cure the illness sweeping Five Points on a grander scale, Doctor Matthew Freeman steps beyond his role as physician. Robert Morehouse finds himself fighting to ensure that a tumultuous chapter of his past is dead and buried, and that he and his loved ones lives will continue to thrive.

Returning to the Precinct, Detective Kevin Corcoran is staggered when he discovers a new investigation has one close to him in chains. Racing to free his friend, Corcoran seeks help from those in power. However, General Brendan Donovan is consumed by an upcoming, major political and business move. Meanwhile, Doctor Matthew Freeman approaches Robert Morehouse to suggest a joint effort to aid the city.