Set in the 1860s New York, an Irish cop works the city's notorious Five Points Neighbourhood.
A career criminal terrorises the Sixth Ward, and Detective Corcoran must put an end to his reign of violence, following the guidance of Ward Leader General Brendan Donovan.
More corpses of young men are found, while other teens continue to disappear, and Corcoran leaves no stone unturned in his search for answers.
Corcoran closes in on those responsible for the kidnapping and murder of young Five Points men, and must choose between the badge and his loved ones.
The Sixth Precinct's search for the murderer of an officer is derailed as Annie creates a fissure in the Corcoran home. Eva Heissen discovers an ally in Brendan Donovan.
Five Points falls into a state of panic as a community safe haven is seized by one of the deadliest men in New York. Corcoran and O'Brien race to restore peace to the Sixth Ward.
A murder demands that Corcoran work closely with Brendan Donovan, who is eager to close the case. Robert Morehouse makes a difficult decision regarding Kennedy's trial.
In his investigation, Corcoran finds himself at an unusual dead end. Doctor Freeman is faced with the outbreak of a new and troubling illness sweeping Five Points.
The greater Copper family, uptown and Five Points alike, gathers around Corcoran, who is reeling from a loss. Freeman steps beyond his role as doctor.
Corcoran is staggered to discover someone close to him in chains. Dr Matthew Freeman approaches Robert Morehouse to suggest a joint effort.
Corcoran questions the motives behind strongholds of the Five Points community, and solicits coppers of the Sixth Precinct to suss out the truth.
Looming devastation to Five Points forces Corcoran to take drastic, irrevocable action. Injuries old and new push Doctor Matthew Freeman to his breaking point.
On the move and evading retaliation, Corcoran works to remain hidden while seeing through events he set in motion. Old loyalties are tested and unlikely friends are made.
In the wake of national tragedy, Corcoran reels along with the rest of the country. Corcoran, Morehouse and Doctor Freeman decide to join a national effort.