Phobos Base Assault
A moon base falls to hellfire, unleashing an ordinary marine's fight for survival.
The Phobos Base Assault is not covered in the source. The source describes Doom: The Dark Ages, a 2025 prequel to Doom (2016) set on Argent D'Nur, not Phobos. The source does not mention any event called 'Phobos Base Assault' or any UAC base on Phobos.
- Protagonist
- Doomguy (Unnamed Marine)
Verified Timeline
Lore & Background
Amidst this chaos, a lone marine—later known as Doomguy—found himself trapped on the surface with no escape route other than through the enemy lines. He was a standard soldier, without any pre-existing superhuman enhancements or Hell Division backstory. The assault on Phobos did not unleash a pre-designed weapon; rather, it thrust an ordinary marine into an extraordinary fight for survival against the demonic invasion.
In Their Own Story
The airlock hissed open, not with the sterile hum of oxygen recyclers, but with the wet, guttural roar of a Cacodemon. The corridor lights flickered and died, replaced by the hellish red glow of fire consuming the research labs. He checked his ammo count; it was low, but his rage was infinite. As the first Imp skittered into view, claws raised to strike, he didn't flinch. He simply raised his shotgun, the sound of the pump echoing like a death knell in the silent vacuum outside.
Reader's Guide
The event begins when the UAC's containment experiments at the Phobos base go wrong, causing a massive rift that allows demons to flood the facility. The initial security forces are quickly overwhelmed by the sheer number and ferocity of the invading entities.
A lone marine becomes the last line of defense as he fights his way through the burning corridors, utilizing whatever weaponry is available to survive. He systematically clears out the lower levels, moving toward the surface where a larger demonic presence has gathered.
The assault concludes with the total destruction of the Phobos base and the escape of the marine. This event serves as the prologue to his journey, establishing the scale of the threat and his unique ability to withstand and destroy hellish forces.
Did You Know?
- Doom: The Dark Ages was announced at Microsoft's Xbox Games Showcase event on June 9, 2024.
- The game uses the id Tech 8 engine and features advanced game physics, which includes destructible environments.
- Music for The Dark Ages was handled by Finishing Move Inc.; the Revelations DLC also featured Whitechapel's Phil Bozeman on vocals.
- Buyers of a GeForce 50 series graphics card of the RTX 5070 and above models were able to receive a free copy of Doom: The Dark Ages until May 21, 2025.
- The Slayer's Praetor Suit is created in the Revelations expansion, powered by the three Ascension Stones.
Development and Release History
id Software began work on Doom: The Dark Ages following the completion of Doom Eternal's post-launch campaign, The Ancient Gods, in 2021, entering full production by August 2022. The game was announced in June 2024, and was released on PlayStation 5, Windows, and Xbox Series X/S on May 15, 2025, to positive reviews from critics, who praised the game's combat systems and setting. An expansion pack, subtitled Revelations, was released on July 7, 2026.
Combat Mechanics and Gameplay Shift
While previous entries in the Doom series, such as Doom (2016) and Doom Eternal (2020), focused on fast-paced, acrobatic combat, Doom: The Dark Ages shifts towards a heavier, more grounded combat experience, emphasizing strategic engagements. The Doom Slayer is portrayed as an 'iron tank', equipped with enhanced melee options and a slow-motion glory kill feature for improved control during combat. The introduction of the Shield Saw allows for blocking, parrying, and attacking within a single input. New weapons include the Skull Crusher, which fires bone fragments. Melee weapons such as a gauntlet, an iron mace, and a flail, are available. The Dark Ages is the first Doom game to allow players to pilot vehicles, like a cybernetic dragon and a 30-story Atlan mech, to combat enemies during certain sections.
Narrative Arc and Character Dynamics
The narrative places a greater emphasis on storytelling, with more cutscenes and character development, providing a deeper insight into the Doom Slayer's origins. At some point following his arrival on the planet Argent D'Nur and his subsequent empowerment, the Doom Slayer is weaponized by the alien Maykrs to assist Argent D'Nur's people, the Night Sentinels, in their war against the forces of Hell, who seek an object known as the Heart of Argent; the Slayer does not fight completely of his own free will, however, as his master, Kreed Maykr, suppresses him with a device called a Tether. The leader of the demons, Prince Ahzrak, realizes it is not worth fighting the Slayer directly and focuses his efforts on finding the Heart. Ahzrak finds the hiding place of the Heart, but the Slayer and King Novik manage to thwart him. However, Novik decides to keep the Heart with himself, not fully trusting the Slayer or the Maykrs. Ahzrak attacks the retreating Sentinel forces. Kreed refuses to deploy the Slayer to help them, intending to keep himself protected. Unwilling to let innocents die, the Slayer is able to break free of the Tether's control, forcing Kreed to send him back into battle, where he successfully holds off the demons long enough for the Sentinels to escape. Ahzrak is able to steal the Heart from Novik but finds it empty and useless. Ahzrak offers an alliance to Kreed, who himself has come to fear the Slayer turning on him. The Slayer attempts to remove the Tether from his armor with little success. Novik's daughter, Commander Thira, tasks him with finding the Heart's power source before Ahzrak does. Thira invokes an ancient ritual to empower the Slayer's shield, and he assaults Ahzrak's fortress in Hell. Meanwhile, Kreed betrays the Sentinels by sending a recording of Thira's ritual to Ahzrak, who realizes that Thira is actually the Heart's power source, and orders her capture. Failing to find Ahzrak, the Slayer returns to Argent D'Nur only to see Thira and Kreed being taken by demons. In order to follow them, the Slayer reawakens an ancient being, known as an Old One, and follows it back to its homeworld, the Cosmic Realm. However, Kreed betrays the Slayer and Ahzrak overpowers him. Ahzrak reveals Thira houses the soul of a Wraith, who are descendants of the Cosmic Realm, and extracts it to power the Heart. Instead of following Kreed's advice to kill the Slayer since the latter cannot permanently die, Ahzrak instead leaves him imprisoned by the Old Ones while he leads the final assault against the Sentinels. The Slayer self-destructs the Tether in his armor, killing himself. His soul is sent to Hell, where he fights his way back to the mortal plane as Commander Valen resurrects him with a demonic ritual. The Slayer kills Kreed, then confronts Ahzrak once again, defeating him and freeing Thira's soul. Ahzrak flees back to Hell, with the Slayer and Thira in pursuit. The Slayer kills Ahzrak, causing his forces to retreat. Afterwards, the Maykrs disavow Kreed's actions while Novik and Valen plan to purge any remaining traitors in their midst. Thira rallies the Sentinels, bidding them not to put their faith in the Maykrs, but in themselves instead. Meanwhile, the Slayer commandeers Kreed's ship to continue his crusade against Hell.
Revelations Expansion and Origins
The Revelations expansion was released on July 7, 2026. The Slayer confronts Hell's High Council, but they use the Slayer's deep-seated guilt to weaken him, and he is defeated by their champion, the Henchman, and banished to a purgatory beneath their chamber. In the purgatory, the Slayer is found by the Architect, who nurses him back to health and repairs his weapons and shield. The Architect instructs the Slayer to collect three Ascension Stones that will cleanse his soul and allow him to escape. The stones reveal the source of the Slayer's guilt: back on Earth, when he was a MARSOC operative, the Slayer destroyed an enemy bunker beneath a hospital, but killed a young girl in the process by mistake; codex logs also reveal the Slayer assaulted his superior officer over the incident, as he was under the impression the hospital was devoid of civilians, leading to him being court-martialed and sent to perform grunt duty on Phobos. The Slayer acquires a replica of Novik's axe, through which he sees Novik being killed by Valen's son, Marok—appointed as the champion of the Maykrs' leader, the Khan Maykr, who secretly allied with Hell and convinced them to stop attacking Argent D'Nur in return for betraying the Slayer. Marok arrives at the purgatory and destroys the Slayer's exit portal; the Slayer defeats Marok, who kills himself before his Tether can reassert control. The Architect turns the stones into a power source for the Slayer's new armor, the Praetor Suit—the suit that the Slayer would use in his later battles against Hell; the Praetor Suit reactivates the portal. The Slayer returns to Argent D'Nur, finding its populace on the brink of a civil war between Maykr loyalists and those who distrust them. He gives the replica to Thira; upon touching it, Thira sees her father's death and orders her forces to rebel against the Maykrs. The Khan Maykr retreats with the Night Sentinels still loyal to her, and summons the Henchman; the Slayer kills the Henchman, and Thira declares war on the Maykrs. In a post-credits scene, unlocked via completing all postgame content, Valen is tormented by demonic whispers; Thira arrives and offers him the axe replica.
Frequently Asked Questions
What event does the Phobos Base Assault describe?
This incident details the moment when demonic entities invaded a scientific station orbiting Mars, wiping out nearly all staff members. It stands as the origin point for the Slayer's long war against the infernal legions.
Where is this battle located within the Doom universe?
The conflict takes place at the UAC Anomaly Research Outpost situated on Phobos, which serves as a moon of Mars. Researchers utilized this specific location to monitor and exploit energy from alternate dimensions.
Who fights against the demons during this initial outbreak?
The central figure is the soldier who would eventually become known as the Doom Slayer. During this specific mission, he operates under standard military designation before embracing his darker destiny.
What caused the facility to be overrun by monsters?
Scientists attempting to harvest energy from other worlds accidentally triggered a system failure that opened gates for the enemy. Security measures collapsed immediately after the breach, allowing monsters to massacre the crew.
How does this story arc conclude for the base and its staff?
The station was ultimately destroyed in the crossfire, leaving no survivors among the original personnel. This tragedy marked the start of a containment failure that spread across the sector.
More in Story & Timeline
Elsewhere in the Doom universe
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