When a rival club cleans out and then destroys their illegal arms warehouse, SAMCRO (Sons of Anarchy Motorcycle Club Redwood Original) executes their own sense of justice in retrieving their guns. Meanwhile, family issues take center stage with a medical emergency involving Jax Teller's newborn son.
Donna's death has the club divided, with Clay setting up a new gun deal with the IRA. Charming and SAMCRO 's hold on the city is threatened after Ethan Zobelle a sophisticated separatist opens a tobacco shop. Zobelle and his less-sophisticated associate are determined to take SAMCRO down due to their black and Latino bikers.
Zobelle comes up with a problem that Hale can solve to frustrate SAMCRO. Meanwhile, Gemma being raped is really affecting her relationship with Clay and the fact that Jax is involved with Luanne's porn business is bothering Tara. Clay decides to give Bobby the responsibility of running the business side of Luanne's.
14 months after going to prison on federal weapons charges Jax, Clay and the other SAMCRO members are released and return to Charming where they encounter new enemies in the form of a no nonsense sheriff and an Assistant U.S. Attorney out to nail the club for their dealings with Russian gunrunner Putlova. Also Jax makes a promise to Tara and Opie and Lyla get married.