Jax is left devastated after the abduction of his son and the Sons try and find out where Jimmy could have taken him. Gemma is hiding in motel protected by Tig and a couple of other bikers when she gets a call from her past – and takes him with her to go see her father who is suffering from dementia. Gemma’s dad can’t seem to get adjusted to the fact that his wife, Gemma’s estranged mother, has passed away and at times thinks she is still alive. The Sons have a funeral for Half Sack and at the end of the wake, masked men commit adrive-by shooting and fatally run down Deputy Hale. Having fled to Belfast with Abel, Cameron confesses his sins to his cousin Father Ashby, an intermediary between Jimmy O and the True IRA Council. Ashby subsequently has Cameron killed, and suggests he will give Abel up for adoption. SAMCRO has an upcoming bail hearing for the weapons charges, but they agree to jump bail. SAMCRO receives an email showing Cameron dead in Belfast. Gemma, having survived a threat by her father’s nurse who comes to know that there is a reward out on her, calls Tara to help her but the two are attacked by the nurse while Tig is away and Gemma kills her. Tig calls a friend (played by Stephen King) to clean up the mess and remove the body.
Gemma struggles when she takes Nate to his new assisted living home, and returns to Charming to reunite with her grandson, still unaware he has been kidnapped. Father Ashby’s sister Maureen contacts Gemma, at Ashby’s request, to tell her Abel is safe in Belfast. Upon learning of her grandson’s abduction, Gemma suffers an arrhythmia and collapses in the Teller-Morrow lot. Tara confides in Gemma that she is six weeks pregnant with Jax’s child. Jax makes a deal with Stahl behind SAMCRO’s back. In exchange for his mother’s freedom and the downgrade of the pending weapons charges against the club, Jax will deliver Jimmy O and his IRA contacts. Oswald agrees to smuggle the Sons to Belfast. Jax breaks up with Tara and the next morning, Tara walks in on Jax in bed with pornstar Ima. After discovering John Teller had an affair in Belfast that produced a daughter, Gemma escapes from police custody with the help of Tara and Tara’s boss, Margaret. Tara and Lyla both make appointments at an abortion clinic. Gemma leaves with SAMCRO on their trip to Belfast to find Abel, where Jimmy O already anticipates their arrival. On SAMCRO’s arrival in Northern Ireland, Ashby tells Jax that the IRA are tired of Jimmy’s profiteering ways, and suggests Jax kill him in exchange for Abel. Stahl helps Jax uncover information on Ashby and SAMBEL, and warns Jax not to kill Jimmy O. SAMCRO plans to surprise Jimmy O on a protection run, but he is forewarned and attacks the Sons with a planted bomb that kills several SAMBEL members. SAMCRO tortures Liam until he reveals that he was privy to Jimmy O’s plans, as was McGee. Jax kills Liam, and shortly afterward Clay pushes McGee from a rooftop; both are revealed to SAMBEL as traitors.
Ashby tells Jax Abel’s location, but suggests Jax allow him to be adopted so he will not be forced into the club life. Jax chooses to leave the child with the family, until Jimmy O kills the adoptive parents and abducts Abel, intending to exchange him for safe passage to America. Abel is returned to Jax after Ashby trades himself for the baby. Salazar & his girlfriend abducts Tara and Margaret on their way to the abortion clinic. He informs Piney that he will return them in exchange for the murder of Alvarez and $250,000. Under the influence of Jacob Hale, Jr., the San Joaquin Sheriff’s Department will soon take control of the Charming Police Department. Tara attacks Salazar’s girlfriend and negotiates Margaret’s freedom. Later, Salazar’s girlfriend dies. SAMCRO returns to Charming with Abel, in time for the weapons hearing which is looming on the horizon. Gemma threatens to reveal Stahl’s murder of Edmond unless Stahl ends her dealings with Jax. Salazar takes Jacob Hale, Jr. hostage along with Tara. Unser indicates the need for Salazar to be captured alive to implicate Hale and save the Charming Police Department, but during a stand-off, Jax kills Salazar. Amidst the chaos, Stahl intentionally shoots her partner Tyler to protect her lie. Opie proposes to Lyla. Now in the USA, Jimmy O seeks the help of the Russian Mafiato aid his escape to South America. Stahl falsely tells Internal Affairs that Agent Tyler shot Edmond and framed Gemma, admitting that Gemma was wrongfully charged. Jax and the Sons meet the Russians and pay $2 million for the exchange of Jimmy O, although most of the money is counterfeit. Jax tells Stahl the location of the exchange so she can intervene and arrest Jimmy, but Jimmy is moved to a different location before she can. Jax assures her that he will give her Jimmy if she reduces their prison sentence, to which she agrees.
Stahl arrives at the clubhouse to arrest Jimmy. When Clay asks how she knew he was there, Stahl indicates that Jax is a rat, which outrages the club, whose members call Jax a “dead man”. SAMCRO is arrested and loaded into an ATF van, with Jax isolated from the other club members. Unser stops Stahl on the roadside as she transports Jimmy and warns her of an IRA threat further down the road. Her fellow agents leave to investigate, leaving her alone with Unser and Jimmy. Soon afterward, Piney, Chibs, Opie and Kozik arrive. Chibs gives Jimmy a Glasgow smile, and then kills him. Opie kills Stahl in a similar fashion, after reminding her that she was responsible for Donna’s death. Proof of Jax’s dealings with Stahl is destroyed, leaving the club with the documents provided by Stahl to reduce their sentence. The scene is set to look like the IRA is responsible. In the ATF van, Jax learns of Stahl and Jimmy’s demise as the prospects following the ATF van ride past and beep a Morse code signal. He smiles, as do the rest of SAMCRO, revealing the club knew of Jax’s plan from the beginning. Tara, meanwhile, finds and reads the letters Maureen had put in Jax’s bag. In them, John Teller writes to Mo of his awareness of Gemma and Clay’s closeness and his fear that they will soon murder him. The season ends with Jax rejecting his father’s original vision for SAMCRO and embracing Clay’s rule. But – Tara finds a stack of letters that Maureen meant for Jax to read; letters that John Teller wrote to Maureen about his fears for the club and about Gemma & Clay!