A grieving Michael Desiato is beyond hope. Eugene is aided by unlikely benefactors. Jimmy Baxter looks to expand his criminal empire while Gina Baxter channels her anger. The arrival of an Assistant U.S. Attorney upends Michael's life.

Michael Desiato discovers a secret while Olivia seizes an opportunity to push him to make a dangerous decision; a desperate business deal threatens Eugene; Elizabeth shelters Michael.

Michael resists a request from Fia, but Olivia pushes him to exploit a newfound connection. Little Mo's deal goes sour, leaving Eugene to pick up the pieces. A face-off between Michael and Jimmy results in a startling confession.

Olivia's plan to get Michael closer to the Baxters sees him invited to Jimmy's 50th birthday party where he witnesses the return of Gina's gangster father.

Following the events at Jimmy's birthday party, Michael vows to quit aiding Olivia. Charlie makes an unexpected move. Little Mo gets on the wrong side of Big Mo after he helps Eugene.

Michael and Elizabeth pursue a lead in Robin's murder case. The Baxters aim to silence Eugene. Jimmy enters into a dangerous alliance. An overdose causes a major rift with Big Mo's lieutenants.

Michael's pursuit of the truth creates life-threatening consequences for him and for Nancy Costello, who has joined him in the hunt for his wife Robin's murderer. Fia faces the hard reality about her family.

Prompted by Olivia, Michael goes to see Jimmy Baxter, who makes him an unexpected offer. Shifting loyalties in Big Mo's crew force her hand. Lee urges Michael for help.

Michael exposes shocking information that impacts everyone. A revelation pushes Fia to make a life-altering decision. Big Mo proposes a deal with Jimmy Baxter. Gina makes a move of her own. Season finale.