Oduwale's killer is uncovered which reveals a devastating personal betrayal to Emily.
Emily realizes that Rex Wolf was working for someone connected to both her past and her present. She finds she can rely on Nick for help, but how to make sense of the puzzle? Emily resorts to extreme measures when she realizes the threat is close to home.
Back in Boston, Emily's grief gives way to purpose as she discovers a clue that connects Rex Wolfe to the mystery of her captivity.
As Emily and Cal journey into rural Moldova, Nick struggles stateside to swallow a massive lie.
Emily and Cal travel to Moldova to track down the Fentanyl Killer-a task that proves to be more dangerous than anticipated. Meanwhile, Nick is given an order that challenges his moral code
While investigating the home of the most recent Fentanyl Killer victim, Emily obtains a critical piece of evidence. Meanwhile, Nick's work with a high-profile prisoner turns deadly.
Emily and Cal's investigation into the Fentanyl Killer points them toward some dangerous and highly skilled suspects. Elsewhere, Nick's manhunt for the Federal Annex attacker heats up.
Emily's investigation into her past becomes a hunt for a serial killer whose crimes have been overlooked in the citywide chaos. When the serial killer claims a victim close to Emily, she returns to the FBI to hunt him down, partnering with Special Agent Cal Isaac a former Navy SEAL with a personality that runs counter to Emily's
Nick and the team try to track down the person who attacked the Federal Annex; a shadow from the past jeopardizes Emily's tenuous balance
Emily Byrne struggles to make sense of her past, including her time held captive; Special Agent Nick Durand is sent to investigate a deadly terrorist attack in the heart of Boston.