PATHOS-II is a sprawling underwater research complex located in the North Atlantic Ocean on the Mid-Atlantic Ridge, and was operated by the Japanese corporation Haimatsu and European corporation Carthage Industries, respectively, with corporate headquarters in Lisbon, offices in New York and London, and a backup site in Cádiz being mentioned on numerous occasions. It is the primary setting of both SOMA and the live-action prequel mini-series and film Transmission and Depth. The facility is located in the Mid-Atlantic Ridge.
PATHOS-II was initially built to conduct thermal mining during the 2060s and, later, developed the Omega Space Gun. It has a diverse staff of scientists and engineers involved in multiple research projects such as marine sciences, hydroculture, and deep sea construction. An artificial intelligence known as the WAU was used to oversee primary operations of the facility.
PATHOS-II was dually operated by two major international private corporations. The first company was Haimatsu, which began the early construction of PATHOS-II and was greatly interested in developing deep-sea mineral resources. Most robotic industrial equipment at PATHOS-II was products of Haimatsu. The other was Carthage Industries, which gradually took control of PATHOS-II and was more interested in scientific research. Carthage Industries provided most of the advanced digital infrastructure for PATHOS-II which gave the WAU its platform to hijack the station. While Haimatsu's ambitions for PATHOS-II were purely economical, Carthage Industries secretly viewed the station as the future of mankind, and instructed its employees within the facility to continue the corporation's identity and mission after Telos destroyed the rest of the world.
When a comet impact infamously known as the Impact Event occurred in January 2103, rendering the surface of the Earth barren and killing all surface life, the staff of PATHOS-II became the last living humans on the planet. Knowing they would not be able to survive indefinitely, they began searching for alternative ways to extend their lives and ultimately, save what remains of the human race - the ARK program being among them. Not much is known about the events that followed, but eventually machines previously operated remotely by humans began to become self-aware and started to exhibit human traits. The facility eventually descended into the nightmarish state seen during the events of the game.
PATHOS-II is a sprawling complex consisting of eight underwater stations and one surface station. Sites Upsilon, Delta, Theta, Lambda and Omicron are located on a relatively shallow section of the ocean floor referred to as the plateau. Tau, Phi, and Alpha are located on the Omega Sector, a small section of the abyssal plain that lies below this plateau owned and operated by PATHOS-II.
- Upsilon - 99m
- Upsilon contains the facility's primary power generation plant. Geothermal boreholes are used to generate electricity. Upsilon also contains extensive facilities used to service and maintain PATHOS-II's collection of robots and Universal Helpers.
- Lambda - 96m
- Little is seen of Lambda in-game, but it is known that Lambda contains a shuttle transit hub that connects all of the other sites. It would have also served as a welcome center for any potential visitors.
- Delta - 64m
- Delta is a small site situated atop an outcropping that extends up from the Abyss. Consisting of several disconnected buildings, a comm antenna and a small control center, Delta is primarily responsible for manufacturing aerodynamic projectile shells for payloads to be launched from the Omega Space Gun.
- Theta - 153m
- Theta is one of the larger complexes, and appears to contain research laboratories, staff living quarters, and administrative offices.
- Omicron - 115m
- Omicron is located on the edge of the plateau, overlooking the Abyss. Omicron is dedicated almost entirely to research, primarily focusing on marine biology, hydroponics, and the effects of structure gel. Omicron also operates the Climber, an elevator used to ferry personnel to and from the sites located in the Abyss.
- Tau - 4114m
- Tau is located in the Abyss, approximately half a kilometer from the lower endpoint of the Climber. Guide lights illuminate a path between the Climber and Tau, used to safely traverse the Abyss without provoking the wildlife. Tau contains several maintenance areas and living quarters for the crew stationed there, as well as a cargo transit system that connects to Phi, originally used for shipping payloads to the space gun.
- Alpha - Depth Unknown
- Alpha is a secret installation, whose existence is not known by all but a select few of PATHOS-II's staff. Alpha is where the WAU's central core is located, and the origin point of its influence across the station.
- Phi - 3802m
- Phi is also located in the Abyss, and primarily houses the Omega Space Gun. Phi possesses a receiving depot connected to the rail system from Tau, used to load payloads into aerodynamic "bullets" which are then loaded into the space gun for launch.
- Omega - 0m
- Omega is a topside installation, situated at the point where the space gun's barrel reaches the ocean surface. Omega is primarily a meteorological outpost.
- "Pathos" translates from Greek, meaning "suffering" or "experience."
- Each station is also named after a letter of the Greek alphabet.
- In the games files, a logo for a Site Mu can be found. The name is also seen in the vertical slice footage of SOMA when Simon is selecting which site to contact in the Upsilon Communications Center. On the People of Frictional: David Satzinger post on the Official blog of Frictional Games, among the early and cut content original logo concepts for the sites on PATHOS-II can be seen, Mu being amongst them. Interestingly, Mu, Tau, and Phi are all solid, meaning that Mu was supposed to be another site in the Omega Sector.
- Considering the 'puddle' underneath the droplet in the Mu logo, it's possible Mu was going to be a site primarily for Structure Gel testing and research, and was ultimately cut when the idea was used in Omicron. However, this is just speculation.
- Discounting the elevation extremes of Alpha, Omega, Phi, and Tau, the average depth of Pathos-II is 105 meters (344 feet) below the surface.