Roarke and Sweeney's fallout splits the Westies, pitting old guard against young; Bridget pushes ahead with the mission but faces shattering truths; Polk increases pressure on Sweeney and Gotti; Keenan wrestles with guilt and a son slipping away.

Tensions between Sweeney and Roarke erupt when one of the Westies is busted; Keenan uses the case to pressure Sweeney and earn Polk's trust; Flanagan's personal life unravels; Bridget pushes deeper into her mission as Cahill's motives blur.

Roarke gets a risky loan from Ruby Stein to fund a cocaine deal with a silver-spooned hotshot from downtown, only for the deal to implode; Keenan targets an older Westie to pressure Sweeney, while Bridget and the IRA cell move on Colonel Markham.

Sweeney lets Roarke sell cocaine only if he sources it himself, putting him in Gotti's crosshairs as Gotti suspects the Westies are defying Castellano; Bridget helps Cahill secure explosives for their IRA plot; Polk pressures Keenan to wear a wire.

Roarke clashes with Sweeney over selling stolen cocaine, but Sweeney has his own agenda; as he receives a Hibernian Society award, Gotti orders a hit; Bridget learns Cahill's target is someone from her past; Keenan struggles to help his son.

Sweeney strikes a deal with Castellano: rob a Colombian disco and Flanagan walks free; Bridget seeks counsel about Cahill, while Keenan investigates the killing of a cop in Boston.

Roarke and the Westies hide the body of a dead Italian mobster and stage crimes to cover up the murder before Gotti retaliates; Polk pressures Keenan to dig into Sweeney's Mafia ties, while Bridget uncovers more of Cahill's plot.

The Westies' fragile deal with the Italians unravels after a reckless kidnapping; Flanagan is released from Bellevue and rejoins Roarke's crew, Keenan is pulled onto an FBI task force, and Bridget receives a dangerous assignment from an IRA contact.