: As you fight through the facility, you discover ruins of an ancient Martian civilization that once fought the same demonic forces. They created a weapon called the Soul Cube , which you must recover from Hell to seal the portal.
The GOG.com version includes both the original base game and the expansion:
: You eventually learn that Dr. Betruger has defected to the side of Hell, orchestrating the invasion in exchange for power.
The core conflict revolves around . Dr. Betruger’s experiments accidentally (and intentionally) open a gateway to Hell . A massive shockwave ripples through the base, instantly transforming most of the UAC staff into mindless zombies and allowing demonic entities to invade the facility. Key Plot Points
You play as a newly arrived assigned to security. The atmosphere is tense; the base is plagued by mechanical failures, "ghostly" sightings, and a workforce on the edge of a nervous breakdown. Tensions are high between the base administrator, Elliott Swann , and the lead scientist, Dr. Malcolm Betruger , over mysterious experiments conducted in the Delta Labs. The Inciting Incident
: The Marine must travel into the heart of Hell, defeat the Cyberdemon guarding the primary "Hell Hole," and use the Soul Cube to close the gateway. Version 1.3.1 [GOG] Specifics
The story of DOOM 3 (v1.3.1) serves as a gritty, horror-focused reboot of the original series. It is set in the year 2145 on the Mars Research Facility owned by the . The Setting and Premise
: Set two years later, a new protagonist (another Marine) is sent back to the abandoned Mars base to investigate a mysterious beacon, leading to a second confrontation with Dr. Betruger (now a demonic entity) and the recovery of the "Artifact." -60% DOOM 3 on GOG.com