Covert operative Tom Keen joins forces with Susan "Scottie" Hargrave. Tom is introduced to the brilliant and cunning chief of a covert mercenary organization that solves problems that are too dangerous for the government.
A plane crash in the Ural Mountains sends Tom and Nez to Russia on a covert operation to infiltrate a mysterious, top-secret military facility; Scottie enlists Mr. Solomon to find answers about her husband.
When ruthless terrorists escape from a secret black site in Manhattan, Tom and the team must lock down the city and find them before disaster strikes. Meanwhile, Scottie uncovers clues that could expose Tom's identity.
On the hunt for a ring of ruthless thieves, Tom and Mr. Solomon must go undercover on an international flight they believe will be hijacked. Howard urges Tom to find proof of a conspiracy orchestrated by Scottie.
When a wealthy businessman and his Family are abducted by professional kidnappers, the Halcyon team is tasked to get the family back. With time running out, the team must make a dangerous choice.
Tensions escalate between Scottie and Howard forcing Tom to reach out to an unexpected ally for help. As explosive family secrets come to light, Tom races against time to learn the truth about Whitehall.
Scottie and Howard battle for control of Halcyon and the dangerous technology tied to Whitehall. Tom clashes with Mr. Solomon as he makes a fateful choice.
