A Turkish cartel informs the Kinsellas that they are obliged to pay a sizeable debt owed to them by Eamon Cunningham. Viking is released from prison intent on making trouble, and a looming presence from inside the family returns.

All hell breaks loose with the unexpected arrival of a family member. While Viking welcomes him with open arms, the rest of the Kinsellas are not so pleased - most of all Amanda, whose leadership is threatened by his presence.

Family loyalties are tested as Brent's influence seeps into each member of the Kinds clan, with Jimmy beginning to take a side as Michael's patience reaches a boiling point. Meanwhile, Viking receives unsettling news and the police gain important information.

With Bren continuing to undermine Amanda's power, and the gardaí focusing their attention on her operations, Amanda is really feeling the pressure. And all that is before she discovers the personal and professional betrayals being conducted against her. Elsewhere, could Kem be in grave danger as under pressure from Bren, Viking pays his old friend a visit? Amanda's lawyer Lauren Bridges meets her and informs her that the guards could be closing in. And finally, Michael's trip to pick up meds from a local pharmacy proves interesting...

Viking is put in an impossible position as Bren puts his allegiances to the ultimate test this weekend. Amanda loses trust in part of the family, and the consequences begin to boil over. The Gardaí move closer to the Kinsellas, and Michael forges an intimate connection. As Frank grapples with his past and struggles with the return of Bren to the fold, things start to spiral. Nikita is cheered up by Viking with a bit of retail therapy.

Viking's allegiances are tested when the gardaí continue to question his girlfriend. Jimmy is unhappy with how Bren is going about the business. Bren seeks out Anna - very much against the wishes of Michael. Meanwhile, Birdy's past and present trauma begin to collide.

Bren's chaos reaches an apex, and the family is driven to mayhem. Michael and Viking both suffer heartbreak, while Uncle Frank seeks a change. The Batuks sew their own discord, and Amanda and Jimmy's son Anthony does the unthinkable.