A young woman is killed on her way home from a lavish yacht party and a suspect is identified as a veteran who had been on several Army operations with Crosby.
Maggie, OA and the team must stop a hacker who is disabling life-saving equipment in several New York City hospitals; Jubal's son waits for important surgery at one of the impacted hospitals.
The team finds a connection between bombings and a private veterans' club in New York City; Isobel tells a reluctant OA to recruit a former army buddy for intel.
The team hunts for a serial killer who is targeting young, homeless men. Also, Tiffany and Scola don't see eye to eye on how to handle the case or the difference between partners and co-workers.
After a suburban woman is kidnapped from her home, the team looks into trysts on both sides of a seemingly perfect marriage; OA feels pressure from Mona to make changes in his career path.
The team must track down a shooter targeting detectives from the same precinct and unit, while facing mounting tension from the NYPD. Also, Tiffany finds that her NYPD roots may be influencing her view of the situation.
After a young girl is kidnapped from her daycare, the team must help her parents navigate a debt owed to the deadly gang in their neighborhood. Also, Maggie struggles to focus on the case when her sister, Erin, returns from rehab.
A widow is shocked that her new "boyfriend" is the manipulative leader of a terrorist group planning an attack; Scola is reminded of his brother's death on 9/11; Tiffany worries about his emotional choices during the investigation.
After Rina is critically wounded while heading to work with Jubal, the team makes the chilling discovery that a vengeful Vargas orchestrated the shooting from behind bars and continues to target the rest of their team and their loved ones.
As the team investigates a string of jewelry store robberies that culminate in a double murder, they uncover a connection to a 16-year-old boy trying to survive the foster care system.
When a Muslim college student and his younger brother are murdered, the team connects with the outraged Imam of OA's former mosque, who insists the victims were wrongly targeted as terrorists.
The team realize they have a cross-country serial killer on their hands; the case has ties to Isobel's father, a hotel chain general counsel. Revelations about their fractured relationship are learned.
After an ICE agent is fatally shot at an ICE vs. DEA hockey game, the team attempts to find the shooter who they believe may also be targeting Congressman Curtis Grange, who was at the same game.
When a retired DEA agent is shot outside a bakery, the team works to determine if the victim's past cases or current bouncer job are connected to the murder.
