When their families mysteriously disappear, Swift and Hawk, teen experts in AI and robotics, are recruited by the secretive Möbius Programme to crack an unbreakable code. They are immediately plunged into a life-and-death rescue mission, that takes them from hidden tunnels beneath the British Museum, to the dangerous docklands of Amsterdam in search of the mysterious ship Nightfall. Caught in a treacherous world of spies and saboteurs, Swift and Hawk will be pushed to the limit as they follow a trail that leads to the remote island of Spøkelsøy, and straight into the hands of a dark and chilling enemy.