Hondo and the SWAT team are forced to work over their Christmas vacation when a drug cartel is out for blood after their cache of gold bars is stolen. Also, Jessica draws the attention of Michael Plank, president of the Police Commission, when she approaches him with her ideas on how to improve the SWAT division.

As the SWAT team goes inside a prison riot to rescue civilian hostages, Hondo suspects the inmates have an ulterior motive behind the uprising. Also, when Deacon’s wife, Annie, stops by headquarters to celebrate Deacon’s 10th anniversary with the SWAT division, her visit takes an unexpected turn.

Hondo and Deacon must apply all their SWAT training and skills to evade a gang of armed mercenaries hunting them in the Angeles Mountains following an ambush. Also, Chris oversteps in an attempt to help a female SWAT trainee she suspects isn’t being evaluated fairly.

The SWAT team sets out to recover dozens of DNA evidence kits stolen from an LAPD crime lab and bring in the crew responsible, after a close friend of Hicks is harmed during the theft. Financial strain at home makes it difficult for Deacon to focus on his role as leader of the SWAT division’s annual holiday toy drive.

The SWAT team faces difficult reminders of a past school shooting when they receive a warning that a copycat plans to re-enact the crime. As the team races to stop the new threat, they flash back to the day of the tense first mission.

The SWAT team discovers a new version of PCP with ties to an escaped drug dealer who created a version that ravaged the city decades earlier. Tan’s personal ties to the case emerge when he brings in his mentor, Ben Mosley, the former lead detective on the original drug case, to help. Also, Chris weighs a major decision regarding her romantic relationship with Kira and Ty, and Hondo’s patience is tested by his new familial responsibilities.

Deacon’s family gets caught in the crosshairs of a drug cartel when he and the SWAT team aim to bring down its leader, a former foreign rebel force leader running drugs in plain sight via a local flower market. Also, Hondo receives troubling news regarding his father, and Tan is forced to go before an internal review board due to his girlfriend’s indiscretion.

The SWAT team’s task to provide security for a warlord is threatened by assassins determined to take him out before he’s extradited by the International Criminal Court. Also, Hondo’s father, Daniel Sr., tries to make amends to his mother, Charice, Street’s foster brother, Nate, asks for his help with a corrupt boss and Deacon reluctantly explores therapy for his daughter, Lila.

The SWAT team races to stop a gunman targeting rehab centers and those he considers responsible for his brother’s death. Also, Deacon is caught off guard when his wife, Annie, makes a parenting decision that has unexpected consequences for their daughter.