In the Season 4 finale, Ray, hoping his deal with Hector will be his family's salvation, learns that Sonia has turned over incriminating evidence to FBI agent Frank Barnes. Ray is forced to wear a wire, but decides to play the Russian mob off the FBI, but things take a dangerous turn. Meanwhile, Mickey's attempt to cash in on the big fight leads him to a discovery that could help Ray against both sides.
Ray's latest attempt to save Avi and square his debts to the mob takes a hit when FBI agent Frank Barnes nabs him before he can pull it off, so Ray must send Mickey to Las Vegas to place a hefty bet on the boxing bout between Hector and Whittaker. Later, in exchange for Federal protection, Barnes offers Ray a chance to turn informant against Dmitri.
Facing a crisis involving one of their own, Ray and the team figure a way to use Kovitzsky-gallery art as leverage. Meanwhile, a distraught Hector calls for Ray's help after his wife decides to move away with their daughter in an effort to get away from the incest scandal.
Ray waits to see if Belikov will be released from prison and struggles with the prospect of putting a pimp back out on the street. Later, Art dealer Sonia Kovitsky invites Ray to a breast cancer benefit where he encounters some former clients and becomes more entrenched in her operation. Meanwhile, Teresa spirals into a postpartum depression; and Mickey tries to persuade the DA that he was the sole architect behind the Minassian massacre.
With the Russian mob threatening his family, Ray goes on a road trip with Mickey to Primm in hopes of recovering money stolen from a local casino owner. Meanwhile, Terry gains confidence as a trainer and gets renewed interest in the gym; and Bunchy and Bridget take turns looking after baby Maria when Teresa withdraws to her family's house to seek refuge from the pressures of being a new mom.
Ray visits a Hollywood power player in an attempt to get the Russian mob off his back and unearths a secret Ezra shared in the past. Meanwhile, Lena and an ex-girlfriend take Abby out on the town to help her confront fears over a recent health diagnosis; and Mickey offers his boys a job prospect and tries to assimilate back into the family.
An intruder breaks into the Donovan household; Mickey plots a casino heist; Bridget celebrates her 18th birthday and struggles to maintain her independence; Ray visits Belikov in prison to strike a deal; Bunchy and Teresa navigate their marital woes under lockdown.
Ray helps Hector handle a person from his past who threatens to reveal a secret that could ruin Hector's boxing career. Meanwhile, Abby offers Bunchy a lesson in marital compromise; and Det. Muncie uses incriminating evidence against the Donovans to force Ray's hand, which draws him further into the path of the Russian mob.
Season 4 begins with Ray in recovery mode in the aftermath of the shootout and trying to reconnect with his family and repair his relationship with Bridget. Meanwhile, Bunchy and Teresa face impending parenthood together; Abby receives a medical diagnosis that threatens to upend the Donovan family; and Mickey plots a heist as Det. Muncie closes in on his hiding place in Nevada.