chunk: In a fog-filled cavern Shall must confront old memories somehow made physically real as long as he believes in them. He has to remain focused on what is true in order to survive. During the ordeal he reunites with Thorvald, who refers to the natives as Wyverns. Together the two men escape from the cavern and Shann saves a young Wyvern from a sea monster.
  Now the Wyverns give Shann a mission. He must extract a Throg from a cave in which it has taken refuge. Shann manages to get the Throg out but is captured by the team sent to pick it up. The Throgs take Shann back to the Terran base and compel him to call the colonization ship that is coming, to lure it down so that the Throgs can kill the passengers and crew. Shann manages to warn the ship and to draw a Patrol cruiser to the base, dooming the Throgs. Before the Throgs can begin torturing Shann to death, Thorvald and the Wyverns envelop them in a fog that realizes their worst fears and kills them.