The message was a shock. "Jackson, Jessamine, you are needed. The Safety of the Realm is at stake." Fresh from their recent adventures, Jackson and Jessamine are on holiday, aboard the luxury cruising-liner, the King Leopold. Their voyage will take them to the fabled Western Isles, lands of mystery and scene of many a recent battle. After what they have been through, it should be a time of rest and recuperation, of seeing the wonders of life in foreign parts. They find that their voyage is filled with intrigue, it appears that everyone has a secret to hide. Then there is the visitor in foreign parts, with his devastating news. They learn that they are needed to fight a new foe, one whose threat is born of a new way of waging war. Something against which the might of Norlandia will have no defence. The plans for the destruction of everything they hold dear must be retrieved and delivered before they can be enacted. There will be no rest for the Orphan Detectives until this threat is dispatched.