Good Behavior follows Letty Raines, a thief and con artist who is always one bad decision from implosion. Fresh out of prison, she's attempting to stay afloat. But when she overhears a hit man being hired to kill a man's wife, she sets out to derail the job, sending her on a wild collision course with the killer.
Fresh out of prison, Letty tries to stay afloat and reunite with her 10-year-old son, who is currently being raised by her mother Estelle. Letty has to show up for mandatory check-ins with her parole officer Christian, whose motives for helping her are questionable. Chaos returns to Letty's life when she overhears a hitman being hired to kill a man's wife, and sets out to derail the job. She soon finds herself dangerously entangled with the killer.
With Jacob finally in their custody, Letty and Javier settle in a quaint beach town; when a hit goes wrong for Javier, Letty must face the reality of being in a relationship with a hit man while trying to lead a normal life.
Javier heads out on his annual solo camping trip to commemorate the death of his baby brother, but Letty discovers that this is a lie and Javier has accepted an assignment; Ava's ex-boyfriend from Argentina shows up amid unusual circumstances.
Letty and Javier go on Christmas vacation with Estelle and Rob to a secluded luxury hotel in the mountains; a man following Estelle threatens the family's holiday; Christian and FBI agent Lashever have their own private getaway.
Letty, Javier & Jacob visit Letty's grandmother Alice to ask her for help with a $50,000 problem. But Alice, a shrewd con artist in her own right, makes Letty work for what she needs and drags Letty into her own con.
Realizing she and Javier only do damage to one another, Letty tries to go back to her old life, but that might be even worse. Javier will use any means necessary to get answers from the person who's been trying to kill him.