chunk: Carruthers and Davies spend some time exploring the shallow tidal waters of the Frisian Islands, moving closer to the mysterious site where there is a rumoured secret treasure recovery project in progress on the island of Memmert. The two men discover that an expatriate Englishman, Dollmann, is involved in the recovery project. Carruthers realises that Davies is in love with Dollmann’s daughter, Clara. Carruthers and Davies try to approach Memmert. They’re warned away by a German navy patrol boat, the Blitz, and its commander Von Bruning. This makes them all the more sure that there is something more than a treasure dig on the island.