Feersum Endjinn
by Iain Banks
The narrative switches between four main characters. Count Sessine is a high-ranking member of the court who is assassinated, ending his last life. Reborn inside the crypt he comes under repeated attack and is almost permanently killed. On his last virtual life, he makes contact with a copy of himself who assists him. He spends many subjective years wandering the wider reaches of the crypt before being contacted by its representative who requests his aid in relation to the encroachment.
Gadfium, the Chief Scientist of the ruling class, is engaged in a conspiracy with like-minded nobles who believe that the elite are not acting in the best interests of the population, and who question the real motive of the ongoing war with the rival clan of Engineers. She learns of a message apparently sent from the fast tower, the highest and previously inaccessible part of the castle, which stresses the danger of the Encroachment and tells of an attempt by the crypt to activate a long forgotten sub system which may prevent disaster. The message also warns that this will be opposed by those in power as it will threaten their interests. She and her fellow conspirators are considering how to respond when the security forces attempt to arrest them, although Gadfium manages to escape into the depths of the castle.
Bascule the Teller is a young man who contacts the dead personalities within the crypt on behalf of their relatives or other interested parties. Whilst searching for a lost friend, he attracts the attention of the Security forces and takes refuge with various chimeric animals whose implants have taken on personalities from within the crypt. He is eventually tasked with ascending the central shaft of the highest tower in a vacuum balloon in order to reach its control room.
Asura is a young woman who awakens in a re-incarnation facility with no memory. She is compelled to travel towards the castle, rapidly gathering knowledge about the world before being captured by the security forces. She is interrogated within the crypt, but is able to resist the questioning, becoming stronger at understanding and manipulating her virtual environments. As she escapes her virtual prison, she is physically freed by Gadfium, assisted by the copy of Count Sessine who guided her to Asura's location. Asura broadcasts to the world the truth regarding the encroachment and the attempts of the monarchy to prevent the activation of the crypt sub-systems. She explains her origin, being an emissary of the crypt that was combined with the mind of Count Sessine who sacrificed himself in the process. She was created by the crypt because the relevant systems were kept separate by their designers to prevent infection by chaos. The so-called chaotic elements of the crypt are a burgeoning ecology of Artificial Intelligences. Asura states that both the humans and chaos will have to learn to live with each other. Asura and Gadfium depart, reaching an elevator which is activated for them by Bascule after reaching the control room at the summit of the tower. Asura is able to activate the "Fearsome Engine" of the title, which begins the slow process of relocating the solar system out of reach of the cloud.