A dead body is found in the mudflats of a North Sea island. As it turns out, the man was an experienced mudflat hiker. Since the corpse does not show any violence, island policewoman Maike Harms could leave the matter alone, but something does not leave her in peace, especially since she is friends with the dead man's daughter. When the officer finds out that the beautiful widow is having an affair, she prides herself. In fact, a dark secret is the key to the death.