Meanwhile Renie and !Xabbu, with the help of Martine Desroubins, have also come to TreeHouse, in pursuit of an old, retired hacker named Singh, Susan Van Bleeck's friend. When they find him, he tells them that he is the last of a group of specialist programmers who built the security system for a mysterious network nicknamed "Otherland," and that his companions have been dying in mysterious circumstances. He is the last one alive.

Renie, !Xabbu, Singh, and Martine decide they must break into the Otherland system to discover what secret is worth the lives of Singh's comrades and children like Renie's brother.

Paul Jonas has escaped from his World War I trench only to find himself seemingly unstuck in time and space. Largely amnesiac, he wanders into a world where a White Queen and a Red Queen are in conflict, and finds himself pursued again by the Finch and Mullet figures. With the help of a boy named Gally and a long-winded, egg-shaped bishop, Paul escapes them, but his pursuers murder Gally's children friends. A huge creature called a Jabberwock provides a diversion, and Paul and Gally dive into a river.

When they surface, the river is in a different world, a strange, almost comical version of Mars, full of monsters and English gentleman-soldiers. Paul again meets the bird-woman from his castle dream, now named Vaala, but this time she is the prisoner of a Martian overlord. With the help of mad adventurer Hurley Brummond, Paul saves the woman. She recognizes Paul, too, but does not know why. When the Finch and Mullet figures appear again, she flees. Attempting to catch up to her, Paul crashes a stolen flying ship, sending himself and Gally to what seems certain doom. After a strange dream in which he is back in the cloud-castle, menaced by Finch and Mullet in their strangest forms yet, he wakes without Gally in the midst of the Ice Age, surrounded by Neandertal hunters.