Magnus Kiljansson is a character who has disappeared in Sea of Darkness.
Magnus's business partner, Dagny Silva, calls Nancy to Skipbrot, Iceland in 2015 to find Magnus after his ship, the Heerlijkheid, crashes into the harbor without him on board. Magnus and Dagny were working together in order to find the treasure that was supposedly hidden on the ship.
Magnus had recently broken up with his girlfriend of four years, Elisabet Grimursdottir. Elisabet says that he was very much obsessed with finding the treasure, and that it would solve all their problems, since he had always wanted a ship of his own and could use it to buy one. Nancy discovers while snooping through Magnus's belongings that he had found something that belonged to Elisabet's ancestor, Captain Lawrence of the Heerlijkheid, and wanted to give it to her, but couldn't until he had figured out how to use it to find the treasure.
Nancy finally finds Magnus in the ice caves near the town. He tells Nancy that Soren Bergursson, the man in charge of the Cultural Center, had abducted him and put him there, hoping he could lead him to the treasure, but since he didn't yet know its whereabouts, Soren simply left him there. After Soren is arrested and Nancy recovers the treasure (having finished Magnus's work and finding the rest of the clues), Magnus takes his half of it and shares it with Elisabet. He apologizes to her for his distance and they go sailing.
- Magnus writes in all caps.