and the dangerous Safeguard response such endeavor may cause, with the means to do so being either climbing stairs for days or taking elevators that reach relativistic speeds. The buildings on each layer are largely uninhabited, although scattered human tribes, rogue Builders, and hostile Safeguards and Silicon Life can be found throughout the entire City. Plot Killy, a silent loner possessing an incredibly powerful weapon known as a Gravitational Beam Emitter, wanders a vast technological world known as "The City". He is searching for Net Terminal Genes, a (possibly) extinct genetic marker that allows humans to access the "Netsphere", a sort of computerized control network for The City. The City is an immense volume of artificial structure, separated into massive "floors" by nearly-impenetrable barriers known as "Megastructure". The City is inhabited by scattered human and transhuman tribes as well as hostile cyborgs known as Silicon Life. The Net Terminal Genes appear to be the key to halting the unhindered, chaotic expansion of the Megastructure, as well as a way of stopping the murderous robot horde known as the Safeguard from destroying all of humanity. Along the way, Killy meets and joins forces with a resourceful engineer named Cibo. Their quest is indirectly supported by the City's Authority, which is unable to stop the Safeguard from opposing them. Together, Killy and Cibo meet a young girl named Sanakan and a tribe of human warriors called the Electro-Fishers. Killy's cybernetic abilities are restored after he is attacked by a high-level Safeguard, which turns out to have been Sanakan in disguise. She transforms into her Safeguard form and attacks the Electro-Fishers' village when discovered. Killy and Cibo defend the Electro-Fishers by bringing them to the cylindrical megastructure of Toha Heavy Industries. Here they meet Mensab, an AI independent from the Administration, and her guardian Seu, a human. The megastructure is ultimately destroyed due to attacks by Silicon Life and Sanakan, but Mensab is able to give Cibo a sample of Seu's DNA. Killy and Cibo next come to a region of the City ruled by a group of Silicon Life, where they ally with a pair of "provisional Safeguards" named Dhomochevsky and Iko. Seu's DNA is stolen by the Silicon leader, Davine, who uses it to access the Netsphere. Dhomochevsky sacrifices his life to kill Davine, but not before she downloads an extremely powerful Level 9 Safeguard from the Netsphere which manifests in