Mason Kane and Nadia Sinh – top agents of the independent spy organization Citadel – collide with a nefarious, new syndicate – Manticore – leading to catastrophe. Eight years later, Mason Kane is living a quiet life as "Kyle Conroy," with no memory of his past. Until one day an old colleague enlists his help to stop a now powerful Manticore from creating a new world order.

Nadia, Kyle and Carter are forced to work together to escape from Manticore and protect the X Case, but suspicion of one of our heroes reaches a boiling point, leading to an explosive reckoning.