Taking advantage of a thick fog, Davies navigates them covertly through the complicated sandbanks in a small boat to investigate the Memmert site. Carruthers investigates the island. He overhears von Brüning and Dollmann discussing something more than treasure hunting, including cryptic references to "Chatham", "Seven" and "the tide serving", and hear of a rendezvous at the Frisian railway station, several days ahead. The pair return through the fog to the "Dulcibella", moored at the island of Norderney. There, they find Dollmann and von Brüning have beaten them and are seemingly suspicious. However, getting in the fog from Norderney to Memmert and back is a nearly impossible feat, which only Davies' superb seamanship could have achieved, and the Germans do not seriously suspect them of having done that.