Renie Sulaweyo, her Bushman friend !Xabbu, and several more of the volunteers recruited by the strange Mr. Sellars have been reunited in the weirdest part of the Grail network they have yet discovered—a world that seems somehow unfinished. They are stranded there because the murderer named Dread, who was masquerading as one of their company, has taken the access device—a virtual object that appears to be a cigarette lighter—that they have been using to travel between simulated worlds.

While they try to discover a way out, two of the more mysterious members of their company, Florimel and T4b, finally explain their backgrounds. Florimel is an escapee from a German religious cult, and has come to the network because her daughter is one of the children (like Renie's brother Stephen) who has fallen into one of the mysterious Tandagore's Syndrome comas. T4b, whose real name is Javier Rodgers, is a former street kid and gang member, now living with his grandparents. A young friend of his has also fallen prey to a coma.

Renie and the others find the unfinished world in which they are marooned increasingly uncomfortable—at one point, they see something that looks just like !Xabbu's baboon sim, but isn't. When a huge hole suddenly opens right in the middle of the ground, almost swallowing the blind woman Martine and somehow obliterating one of T4b's virtual hands, they decide they must escape immediately. Martine, !Xabbu, and Renie, working together, manage to open a gateway even without the lighter.

After they step through the gateway, following in Dread's virtual tracks, the search-and-destroy program named Nemesis, which was put into the network to locate another fugitive, Paul Jonas, tries to decide whether to follow them or not. It is confused—there are things happening on the network that interfere with the original clarity of its programmed drives, anomalies that are making it do strange, unprecedented things.

The amnesiac fugitive Paul Jonas is living out a version of the Odyssey in which he is Odysseus, returned to his home island of Ithaca after the Trojan War. But Penelope, the wife of Odysseus (who also appears to be yet another incarnation of the mysterious woman Paul thinks of as "the Angel") does not seem to be playing by the same set of rules. In an effort to shake her up and get some answers—another incarnation of the Angel has told him that the Penelope-version will tell him how to find the "black mountain" he must reach—he performs an invocation of what he thinks is Hades, the death god of ancient Greece. Instead, he summons the Angel herself, confronting Penelope with a near-twin. Next, a new force answers his invocation—not Hades, but the Other, the dark intelligence behind the Grail network. Terrified, Paul flees onto the ocean, but his boat is destroyed.

Meanwhile, Orlando Gardiner and his friend Sam Fredericks are in a simulation of ancient Egypt—a simworld that is the one place on the network that Felix Jongleur, the world's oldest man and master of the Grail Brotherhood, considers his home. They have been hidden from Jongleur's subordinates by a woman named Bonnie Mae Simpkins who is a member of a group called the Circle. She tells them how her husband and many other Circle members have been killed trying to penetrate the mysteries of the Grail network. Now the last few members in Egypt are besieged in a temple. Bonnie Mae recruits the god Bes to lead her and Orlando and Fredericks there, hoping that her Circle friends can help the two teenagers escape Egypt through an activated gateway.

People offline are just as involved in these events as those trapped on the network. Catur Ramsey, a lawyer who works for Sam Fredericks' parents, finds himself drawn deeper and deeper into the Otherland mystery. With the help of Orlando's software agent, a cartoon bug named Beezle, Ramsey follows the online trail of the two comatose teenagers. A Canadian woman named Olga Pirofsky that he contacts, who works for one of Jongleur's many companies, has also become involved. What started for her as troubling headaches have now become dream-visitations by mysterious children. Olga fears she might be going mad.

In North Carolina, the little girl Christabel Sorensen, who helped Sellars escape and hide under the military base where they both live, has been caught by her security chief father, Major Sorensen. Sellars uses the little homeless boy Cho-Cho to ask Christabel to arrange a conversation with her parents. Sellars tells—and shows—Christabel's parents enough to convince them to help him escape the base entirely. With Sellars hidden in the back of their van, and Cho-Cho pretending to be Christabel's cousin, they all set out for a rendezvous with Catur Ramsey, who has also been contacted by Sellars.

Back in the Otherland network, Renie, !Xabbu, and the others have come through their jury-rigged gateway, following Dread's trail into a mysterious simworld known only as the House. They quickly discover it's called that because the world is nothing but a house—an endless collection of halls and rooms, with separate civilizations living only floors apart from each other. They are assisted in their queries by a brotherhood of monks who maintain the House's monstrous library, but Martine is kidnapped by Dread, and with the aid of one of the monks they set out in search of her—and the murderer.

Someone else searching for the murderer Dread—although in the real world, not the virtual—is Calliope Skouros, an Australian homicide detective. In the course of investigating one of Dread's earliest killings, she begins to find out just what a strange and unpredictable killer he is. Although Dread—also known by his birth-name, John Wulgaru—is listed as dead in police records, Calliope begins to suspect that he is alive.

Dread is not only alive, but has returned to Sydney, setting up operations only miles from Detective Skouros. He has brought the American programmer Dulcie Anwin to Australia to help him make sense of the Otherland network, whose existence he discovered while eliminating one of Felix Jongleur's Grail Brotherhood rivals. Dulcie finds herself strangely attracted to Dread—she knows he is a criminal, but has no idea of his true proclivities—and Dread is more than willing to use that attraction for his own benefit. He has big plans for the network, and plans to use his experience there as a basis for overthrowing his employer, Jongleur. He sets Dulcie up in a loft and puts her to work.

In South Africa, Renie's father Long Joseph Sulaweyo and friend Jeremiah Dako have been guarding her and !Xabbu while they lie helpless in the V-tanks they have used for long-term access to the network. But Long Joseph, cut off from drink, miserable, and distracted, left the abandoned army base to head for Durban and was kidnapped outside the hospital where his son Stephen lies comatose. The kidnapper turns out to be Renie's ex-boyfriend Del Ray, whose own life has been ruined by the help he gave Renie. He is desperate to find Renie so he can get a group of thugs (whom Dread hired on behalf of Jongleur) off his back. But when Joseph and Del Ray leave the hospital after going back to see Joseph's son, they are trailed by a mysterious black van. Then, when they return to the army base dug deep into one of the Drakensberg mountains, they find the thugs are there ahead of them. Joseph and Del Ray sneak into the base through the air duct Joseph used in his escape. Inside the base, Jeremiah has been contacted by Mr. Sellars, who wants to help them, but things do not look good. All but weaponless themselves, they are now besieged by heavily-armed killers.