When a robbery crew holds up the iconic downtown Los Angeles library, the team discovers that stolen architectural drawings could lead to a major threat against the city. Also, the squad is surprised by the arrival of a new leader, longtime LAPD veteran and former S.W.A.T. member Rodrigo Sanchez.

When hospital employees are targeted by a gunman, the SWAT team races to find a grieving father whose son was denied a kidney transplant; Hondo searches for evidence behind an alarming rise in Los Angeles stash houses.

When a series of deadly explosions hits oil derricks across Los Angeles, the team must hunt down an activist-turned-terrorist; Deacon and his wife work to free a reformed drug dealer who they believe was sent away for a murder he didn't commit.

A blackout throws the city into chaos, forcing 20-Squad onto the streets for an emergency patrol day, which quickly escalates when Hondo and team uncover a terror threat.