After her boat is found floating on the lake, an extensive search gets underway for Maud van Keulen. Is there a connection between her disappearance and the possible return of Olaf Witte? The Criminal Investigation Department is called in to help. Then something is found on the water.

Now that the mystery man is starting to regain some of his memories, it seems that he is still Olaf Witte. But DNA research once again shows that he cannot be Olaf. The investigation focuses on an area where there used to be allotment gardens. Who visited the gardens around the time that Olaf and Alice disappeared, and did something happen to them there?