Scottie Hargrave recruits Tom Keen to her elite team of covert operatives on a mission to rescue a CIA agent, but Tom Keen has a mission of his own - to uncover the conspiracy within his family.

The Halcyon team scrambles to rescue Scottie's close family friend after he's falsely arrested for espionage in a dangerous foreign country.

A plane crashes in Russia's Ural Mountains, prompting Tom and Nez to go undercover in Russia to infiltrate a shadowy top-secret military facility. In other events, Scottie enlists Mr. Solomon to unearth information about her husband.

Ruthless terrorists escape from a black-site prison in Manhattan, so Tom and the team lock down the city and try to track them down. Meanwhile, Scottie unearths clues about her late husband that could expose Tom's identity.

Ruthless thieves who steal classified material are targeted by Tom and Mr. Solomon, who go undercover on an international flight they suspect will be hijacked. Meanwhile, Howard pushes Tom to probe a potential conspiracy orchestrated by Scottie.

Professional kidnappers abduct a wealthy businessman, his wife and young son. The Halcyon team members scramble to get the family back and, with time running out, they must make a dangerous choice. Also: Tom risks exposure to save Howard.