When informants for the Sherriff's Department start turning up dead all over Los Angeles, everyone has to work together to find the leak in the department. Meanwhile, Teresa and Cade deal with a major setback in the custody battle for their foster children. Also, on the day of Maggie's Quinceanera, Bill gets stuck in a difficult position between work and family in the season finale

Charlie, Joseph and Carter investigate a case that becomes more complicated at every turn, while Bishop and Cade make a connection to a homicide they never expected. Still suffering flashbacks from the hospital takeover, Paula tries to find closure. Meanwhile, Bill's family strives to humanize him to the constituents of Los Angeles County

When Charlie and Joseph arrest a man on his way to a major drug deal, they end up bringing a bigger fight than expected back to the station. Meanwhile, Cade and Teresa continue to deal with the complication in the adoption of their foster children and Bill comes to a big realization about his job as Sheriff, as the window on his term continues to close.

When one of Charlie's mentees from the local library gets mixed up with a gang, Charlie ropes in the whole team to help save her life. As Bill's term draws to an end, other players continue to enter the race for power. Meanwhile, Cade and Teresa are struggling to deal with an unforeseen situation with their foster children.

When a rash of home invasions hit West Hollywood, it leads the Sherriff's department to discover a burglary ring, whose members are competing against one another for bragging rights. Paula and Maggie continue to plan Maggie's Quinceaera, enlisting the help of Paula's mother. Meanwhile, Bishop tries to deal with an uncomfortable conversation with Genevieve.

When an ex-marine turns up dead on the street, Bill helps Cade work the case that hits far too close to home. With other candidates waiting in the wings to take Bill's place as sheriff, the department pressures him to be more of a team player. Meanwhile, Paula and Maggie see a counselor to try to deal with the repercussions of Bill's new position.

When a massive fire breaks out and the LAFD needs the help of the Sheriff's department, one of Bill's deputies discovers a suspicious car in the forest that leads them to a missing girl. Maggie learns the consequences of Bill's new job when reporters stake out their house for answers. Meanwhile, Cade and Teresa try to figure out the best way to broach an uncomfortable conversation with their foster children

When a gunman walks into the medical wing of the Los Angeles Correctional Facility - where Paula is volunteering - Bill has the entire Sheriff's department look for a way to get her out. Meanwhile, with only three months left in Bill's temporary stint as Sherriff, others decide to make a run for the role.