Eight years ago, "Citadel" fell. The independent global spy agency - tasked to uphold the safety and security of all people - was destroyed by operatives of Manticore, a powerful syndicate manipulating the world from the shadows. With Citadel's fall, elite agents Mason Kane and Nadia Sinh had their memories wiped as they narrowly escaped with their lives. They've remained hidden ever since, building new lives under new identities, unaware of their pasts. Until one night, when Mason is tracked down by his former Citadel colleague, Bernard Orlick, who desperately needs his help to prevent Manticore from establishing a new world order. Mason seeks out his former partner, Nadia, and the two spies embark on a mission that takes them around the world in an effort to stop Manticore, all while contending with a relationship built on secrets, lies, and a dangerous-yet-undying love.