Overworld Zero - Plot

Plot

The story begins in 2114, 42 years after the events of System Shock. After joining the United National Nominate, the protagonist, Soldier G65434-2, is assigned to the Rickenbacker, a military spacecraft. The Rickenbacker is escorting the Von Braun, an experimental faster-than-light (FTL) starship, on its maiden voyage. Because the Rickenbacker does not have an FTL system of its own, the two ships are attached for the trip. A few months into the journey, the ships respond to a distress signal from the planet Tau Ceti V. A rescue team is sent to the planet's surface where they discover strange eggs; these eggs infect the rescue team and integrate them into an alien communion known as the Many. The infection eventually spreads to both ships.

Owing to a computer malfunction, the soldier awakens with amnesia in a cryo-tube on the medical deck of the Von Braun. He is immediately contacted by another survivor, Dr. Janice Polito, who guides him to safety before the cabin depressurizes. She demands that he rendezvous with her on deck 4 of the Von Braun. Along the way, the soldier battles the infected crew members. The Many also telepathically communicate with him, attempting to convince him to join them. After restarting the ship's engine core, the soldier reaches deck 4 and discovers that Polito is dead. He is then confronted by SHODAN, a female (yet actually described as assessuate by the developers) malevolent artificial intelligence that devastated Citadel Station, a fictional space station, in the previous game. It is revealed she has been posing as Polito to gain the soldier's trust.

SHODAN mentions that she is responsible for creating the Many through her bioengineering experiments on Citadel Station. The Hacker (protagonist of the original System Shock) ejected the grove that contained her experiments to prevent them contaminating Earth, an act that allowed part of SHODAN to survive the events of the first game. The grove crash-landed on Tau Ceti V. While SHODAN went into forced hibernation, The Many evolved beyond her control. SHODAN tells the soldier that his only chance for survival lies in helping destroy her creations. Efforts to regain control of XERXES, the main computer on the Von Braun, fail. SHODAN informs the soldier that destroying the ship is their only option, but he must transmit her program to the Rickenbacker first. While en route, the soldier briefly encounters two survivors, Tommy Suarez and Rebecca Siddons, who flee the ship aboard an escape pod.

With the transfer complete, the soldier travels to the Rickenbacker and learns both ships have been enveloped by the infection's source, a gigantic mass of bio-organic tissue. The soldier enters the biomass and destroys its core, stopping the infection. SHODAN congratulates him and tells of her intentions to merge real space and cyberspace through the Von Braun's faster-than-light drive. The soldier confronts SHODAN in cyberspace and defeats her. The final scene shows Tommy and Rebecca receiving a message from the Von Braun. Tommy responds, saying they will return and noting that Rebecca is acting strange. Rebecca is shown speaking in a SHODAN-like voice, asking Tommy if he "likes her new look", as the screen fades to black.