The TU storyline revolves around the planet Acheron on which human colonists have set their foot on approximately 350 years before the events of the main campaign. Player follows these events in the main campaign as Katana, young Imperial commander. The viewpoint differs during the Events, when another characters are played:
- for Imperial, the playable characters are Halcyon, Tabitha, Octane.
- for Raiders, the playable characters are Yurich, Typhon, Barracus, Svetlana.
- for Righteous, the playable characters are Empress, Kathryn.
- arguably, the playable character for Bloodthirsty is Gore Typhon.
- 1 Before Acheron's colonization
- 2 The first century
- 3 The second century
- 4 The third century
- 5 The fourth century
- 5.1 Phobos Rising
- 5.2 Asphodel Garrison, Asphodel Siege, Asphodel's End
- 5.3 Rise of the Ancients
- 5.4 Swarm of the Forsaken, Blood Harvest
- 5.5 Heart of the Enclave
- 5.6 Divine Awakening
- 5.7 Alpha Rebirth
- 5.8 Main campaign
- 5.9 Worldship Invasion
- 5.10 Infested Worldship
- 5.11 Secrets of the Worldship
- 5.12 Tartarus Crusade, Tartarus Vengeance
- 5.13 Dimensional Terror
- 5.14 Tabitha's Exile
- 5.15 Escape from Arctis Prison
- 5.16 Valhalla Ascension
- 5.17 Spawning in Sulfuris
- 5.18 Invaders of the Wasteland
- 5.19 Sins of the Divine, Progenitor's Continuum, Harrowing Journey
- 5.20 Attack on Ashrock, The Phobos Heist
- 5.21 Eden Breached, Nexus of Eden
- 5.22 Alpha Infection, Typhons Destruction
- 5.23 Vaults of Valhalla
- 5.24 Storms over Avalon
- 5.25 Sons of the Fallen
- 5.26 Armada Arrival
Before Acheron's colonization
Only a little is known from this era. Humans became a spacefaring civilization known as the Imperials and eventually came across a Xeno signal, which was the beginning of a large-scale interplanetary war. The colonization process continued, though, and Acheron became one of those new colonized worlds due to seeming absence of Xenos.
The first century
- 0 AD - Acheron is colonized by the Imperials.
- 40 AD - Acheron Colonies lose contact with other Imperial worlds. Ships sent into orbit disappear.
- 100 AD - The Colonies lose leadership and cohesion. The Splinter War (war between the Acheron colonies) begins.
The second century
- 140 AD - The Children of the Throne colony splits and heads west claiming that they found new leadership. They find the Pantheons and isolate themselves and are gradually influenced by ancient technology.
- During their first explorations of Acheron the Children of the Throne colony discovered the slumbering Progenitors in Arctis. Their leader had communed with the ancient technology within the temple and the colony was taught the ancient secrets by the databases of Pantheon.
- 200 AD - A Nexus is discovered in Asphodel lands, but the Asphodel leadership refuses to activate it.
- Gavron Vex with his people reaches Asphodel to find out it is inhabited by Progenitors, who force his fellow travellers to join local people already under Progenitor's control and to attack Vex. Vex faces Savage Anicetus in an attempt to break Progenitor's control over them.
- Jakob, Gavron's lieutenant now under Progenitor's control, states that the land is doomed, reciting a cryptic prophecy. Gavron Vex refuses to leave and attacks Alexiares Regent.
- The prophecy says: "A single power drives all to desire. A single torch consumes a forest once lit. A single ember burns in the ashes. A single wind carries it to another. A second flame chokes the world in smoke."
- It is a reference to Halcyon who burns Asphodel down in the future because of his desire for the Nexus, while setting Gavron's descendant, Typhon Vex, onto the path of revenge.
- Jakob, freed from Progenitor's control, confirms that they are guarding Primal Nexus from falling into wrong hands. Gavron Vex seizes it, claiming he replaces them in their duty as the Nexus guardians, refusing to activate it himself.
- Event's epilogue describes Asphodel to be a lush country rivaling even Orion (supposedly the former capital of Acheron), providing help during battles with Bloodthirsty, but staying strictly neutral regarding man-made wars until its fall in 335 AD.
The third century
- 210 AD - First contact with the slavering Bloodthirsty. They seem to bubble out of the earth.
- First blighted human was found at Outpost 331 in the Swamp Lands.
- 215 AD - Camps across Acherons mainland see increased attacks from Bloodthirsty.
- 217 AD - The Prometheus device is created to combat the Bloodthirsty. It fails.
- 225 AD - The Children of the Throne reappear and declare themselves Righteous. They begin a campaign against the Bloodthirsty and those deemed sullied by the Blight.
- Some time during this campaign, they tried to slay Oluth and to reclaim the Bloodthirsty-infested city of Orion, but they failed. Six Sentinels attempted to incorporate Bloodthirsty's methods into their own, but were eventually destroyed by the rest of the Righteous. Heretic groups supporting these Sentinels, such as the Nephilim, remained, although in secrecy.
- 260 AD - A small Enclave squadron appears in the skies and begins monitoring Acheron. Something on the planets surface has attracted the Xeno.
- 300 AD - The Unification Forces are founded. They seek to reunite the Colonies.
The fourth century
- 310 AD - The Red Maw faction attempts to stop the UF from bringing the colonies together.
- 313 AD - More Xeno ships begin to appear in orbit around the planet.
- 320 AD - Kor Prison is created for exiled prisoners of war.
- 323 AD - Xeno Enclave ships go silent. It's believed they have entered cryo-sleep.
- A young Imperial commander Halcyon oversees the completion of the Phobos Station by a former Red Maw scientist Aria, which is intended to be the weapon against the Red Maw. Red Maw leader Vargas attacks the Spire in order to prevent it.
- Halcyon and Aria defeat Red Maw's General Agmeus. After that they head for Vargas himself.
- After defeating Vargas, they find out that his ultimate weapon, GDR-5000, is activated and heads for the Spire to prevent the launch of Phobos. Aria sacrifices herself to damage GDR-5000, so that Halcyon and his men can finish it off.
- 325 AD - The Red Maw is defeated, UF gain control of the Spire. They reclaim the name Imperial.
- 334 AD - Halcyon sets his sights on the Asphodel Nexus. Asphodel refuses to cooperate with the Imperials.
- 335 AD - Imperials attack Asphodel to gain control of the Nexus.
- Halcyon lays waste to Asphodel by activating the Prometheus device and causing the Nexus to explode. Asphodel is known as the Wasteland from now on.
- With the King Orthrus Vex of Asphodel dead, his son prince Typhon Vex tries to flee and regroup, but is captured by Imperials and with the displaced people of Asphodel sent to Kor. Halcyon becomes the Grand Commander.
- In order to protect his people from Kor prisoners, Typhon Vex manages to kill the prison boss and declares himself the leader of the people of Kor and Asphodel.
- People of Kor adopt the name Raiders and are attacking the Imperials in vengeance for imprisoning them.
- During one of the Raider ambushes Typhon discovers about the Prometheus device.
- Meanwhile, Halcyon is sending Tabitha and Octane on various missions.
- Octane and Tabitha travel to Arctis in search for Neocyte and fight the Righteous protecting it.
- The Righteous awaken the Progenitors that have been slumbering here, and activate Serapherus and Pantheon. Both foes are destroyed, but Pantheon manages to summon the first Sentinel - Jotun.
- With the Pantheon destroyed, Jotun is vulnerable, and the Imperials defeat him.
- Tabitha and Octane arrive in Sulfuris hunting Bloodthirsty to meet Yurich, who is sent here to stop the Forsaken, an outcast faction of Raiders. They temporarily team up to reach this goal.
- The team destroys Vitriol and N.O.X. and shuts down the refinery, but are unable to stop activating the Pandemonium.
- Yurich intends to seize the Pandemonium and use it against the Forsaken. When rejected by Tabitha and Octane, he turns against them, but is defeated.
- Tabitha and Octane destroy Pandemonium, but fall into the Cavern of Blood in the aftermath. They get surrounded by the Bloodthirsty they were tracking.
- After beating Insidious, they head for the possible exit. They encounter Yurich once more, who apologizes for his betreyal, and joins them again in their search for escape.
- The team defeats Mammon, who was guarding the cave entrance, but in order to escape they need to reach the scallable wall on the far side of the cavern.
- In order to reach this wall, Octane kills Mephistopheles to use his body to climb out.
- Octane and Tabitha warp to the Xeno Homeworld in an attempt to stop the Xeno invasion.
- They find out that Xeno homeworld is covered in Blight and the Xeno are fleeing it. After the fight with Rastax they are shot down and forced to make a crash landing on the surface.
- Octane distracts the approaching Razogoth, a massive Bloodthirsty, in order to get more time for Tabitha to repair the shuttles.
- After they take off of the planet surface, they continue their mission. In order to close the portals, they need to kill the Xeno High Admiral Excelsitus.
- They manage to fatally wound Excelsitus's ship, before they set their ship on autopilot and escape through one of the closing portals.
- Tabitha wakes to find herself alone in Swamp Lands. She then encounter the Righteous sect intending to summon the Divine Sentinel.
- She defeats Heimdal and Octane finds her and teams up with her afterwards. He reveals that these Righteous present a sect that intends to destroy Acheron instead of purging it.
- Together they defeat the carrier Evrane, but the Righteous manage to summon Shiva anyway. Tabitha and Octane then intercept it before it reaches Acheron's surface.
- Tabitha and Octane arrive on Alpha Island investigating strange energy readings to discover all the factions here being controlled by Progenitor Alexiares.
- Barracus and Yurich also arrive here to find Malika in preparation for Typhon's assault on the Spire. They encounter Anicetus.
- The first Progenitor, Alpha, revives and is defeated by the combined forces of Imperials and Raiders.
- ~355 AD - Typhon invades the Spire as a distraction to search for the Prometheus device in the Baron's Claw labs. A young Imperial commander Katana is sent to track him down.
- Typhon retrieves the Prometheus and frees the Brood Mother to cover his escape.
- The Imperial pursuit defeats the Brood Mother in the Swamp Lands, being attacked by the Righteous.
- The Imperials are following Typhon to the Wasteland, where they meet up with Octane, and together they fend off the Xeno attempt to use the Nexus to create the Warp Rift that would allow them to bring their fleet.
- Typhon, whose intent was to activate the Wasteland Nexus, is defeated, but manages to escape to Kor with the Prometheus device.
- Upon reaching the Kor, Katana recieves order from Halcyon to kill the Raider civilians, which she refuses and teams up with Yurich, the Raider commander opposing Typhon, instead.
- Katana, whom Halcyon now considers a traitor, fights Halcyon as they both pursuit Typhon across Sulfuris.
- Katana fights her way through the Xeno mines under the Razor Mountains that lay between the Blightlands and Sulfuris.
- Katana follows Typhon through the Blightlands being attacked by Bloodthirsty, who ignore Typhon, and Righteous.
- Typhon manages to activate the Nexus and warp them all to Tartarus.
- Katana continues her pursuit of Typhon through Tartarus. Typhon reaches the Tartarus core, merges with it and becomes Gore Typhon.
- Katana and her allies manage to escape to Arctis. They find out about the plan of Righteous to summon the Sentinel, which would wipe out all life on Acheron.
- Katana fights through the Righteous defenses and destroys the Pantheon.
- Katana and her allies head towards the Xeno Worldship. After disposing of the Raiders that managed to sneak on their ship, they reach the Worldship.
- Katana manages to fight her way into the room that houses the Worldship's database. After decrypting it, it's revealed that the Worldship was homing into the Typhon's Blight as the beacon.
- Katana escapes from the Worldship and takes it down with the explosives she had placed on it. The Worldship crashes near Kor.
- Katana and Yurich try to reach Kor, but Lord Silus, the current leader of Raiders that is opposing Typhon, tries to stop them. He eventually challenges the duo to fight with him personally with the reward of him joining their ranks.
Except for the main campaign, there was also an event regarding the Worldship as well. It is unclear whether there were two of those, whether there were two simultaneous attacks against it, or whether one of them is considered non-canon.
- Halcyon interrupts his awarding of Octane and sends him and Tabitha to destroy the Worldship.
- They steal the Xeno transport and seize Wyrmhold, an outpost deployed by the Worldship.
- After shooting down Rastax, the duo identifies and destroys the Worldship stabilizer. Without it the Worldship is unable to enter the atmosphere and crashes.
- Tabitha and Octane are sent to salvage the remains of the fallen Worldship, only to find the Bloodthirsty merging with it.
- Seeing that as a serious threat, the duo slays Kraken and Blightbloom even when Halcyon aborts the mission, suggesting that Raiders should take care of it.
- They continue on their path to detonate the Worldship's core, but are encountered by Infested Rastax. While Tabitha fights Rastax, Octane detonates the core and wipes out the threat.
- After the Worldship's core detonation, the Righteous being lead by Empress try to salvage the ruins for themselves. Their operation is interrupted by Colossal Kraken.
- While further excavating the area, they are ambushed by the Xeno lead by Valefor.
- After Valefor's defeat they discover The Fury, an ancient Xeno. They defeat him and acquire his power with the intention of using it against the Blight.
- The Righteous are trying to reach the Tartarus core with Core Carrier being protected by Convoy Eos.
- The core that the Righteous are carrying is apparently the one found in the Worldship ruins.
- When Barracus defeats his foes, the Righteous deploy thir last asset, Deidon. Barracus destroys it as well.
- The Bloodthirsty that Typhon is controlling were irritated by the presence of the Righteous in such way, that they grow out of Typhon's control.
- Barracus needs to defeat the newly formed Bloodthirsty in order for Typhon to keep control of them. Barracus slays Blightbloom Venus as well as Infested Eos.
- An ancient Bloodthirsty, Kalihmah, emerges and posseses Barracus, but is forced to retreat by Typhon.
After these events, Barracus Lost side-missions take place, describing how Typhon turns against Barracus for attacking him while being possesed by Kalihmah. Typhon spares his former ally's life but casts him out of Tartarus. At some point after that, Typhon himself submits to Kalihmah, becoming Gore Typhon.
- Halcyon and Octane discover that Xeno ground forces are invading the Spire in order to create portal to their homeworld. Halcyon reluctantly evacuates the Spire and together with Octane faces the Xeno general Octix.
- After halting the first wave of the invasion, Halcyon and Octane find and destroy Fissure, that was preparing to open the portal to Xeno homeworld.
- Even with Fissure destroyed, the portal is still open. Halcyon and Octane push the Xeno forces back into the portal, until they fight Arachis that was just emerging from it.
- Tabitha refuses Halcyon's command that would apparently harm the Imperial allies and is forced to flee around the Cain's Outpost.
- Halcyon orders Octane to kill Tabitha using Octane's Tank. Octane suggests only to apprehend her, but Halcyon refuses and demands her to be killed. Octane refuses and joins Tabitha.
- They escape together, but not until they fight off The Intrepid, the Imperial flagship chasing them.
- The Righteous Kathryn attempts to free her comrade Emrys from the HyperSec prison.
- She succeeds, but they are intercepted by Steel Sheriff on their way. After his defeat, they encounter The Warden as their final obstacle to freedom.
Prior to these events, Kathryn and Emrys encounter betrayed Barracus during Barracus Found side-missions. They ease his pain of being betrayed and also purify him from the Blight remnants. Barracus joins their ranks as Barracus Risen.
- Barracus Risen accompanied by Kathryn and Emrys marches towards the Valhalla Station. Halcyon with Nicolas fight Armament and shortly after Barracus himself.
- Barracus Risen is defeated, but before Halcyon can kill him, Nicolas reports of Emrys reaching the summit of the mountain. Before Halcyon has a chance to react, Kathryn ambushes and kills Nicolas.
- Meanwhile, Emrys has reached the summit of the mountain and completed the ritual, which transforms him into Emrys Ascended - the human Pantheon.
Spawning in Sulfuris
- Apparently in search for the useful technology to fight Typhon, Yurich and Svetlana are sent to do a routine patrol at Sulfuris to find it crawling with Bloodthirsty.
- While fighting Belphegore and Wrath, it is revealed that the previous temporary alliance with Imperials had a great impact on Yurich, as he describes those events to her, noting that 'they were not like the others' and that 'they were different like we are from our bretheren'.
- Restored Mephistopheles then emerges and is slain by the duo.
Invaders of the Wasteland
- Shortly after the events of Spawning in Sulfuris, Yurich and Svetlana are sent to the Wasteland to intercept Xeno in that area and salvage as many of their technology as they can. In order to spread chaos among the Xeno they assault their general Octix Returned.
- Octix escapes, and while trying to pursue him Raiders run into Malaphir, Xeno drone releasing platform.
- Barracus Siege side-mission also takes place here. Barracus appears in the Wasteland and endangers the operation (?).
- While battling Malaphir, Nexus Arachis is pulled from the portal (leading to Tartarus?).
- Octane and Tabitha are back on the Alpha Island to find Righteous here. When they are discovered, the Righteous deploy Heimdar to stop them.
- After Heimdar and even the second guardian, Dactyl, falls, Patriarch must stand to protect the Olympus fragment - Progenitor device - from them.
- It is revealed that Olympus fragment has transported them to a twisted version of Ashrock controlled by Progenitors. While fighting through various foes, they eventually encounter Mammon Sire.
- They decide to shut down the Spire construction, but have to fight through GDR-SIRE first.
- After the defeat of GDR-SIRE, Progenitors take control of Tabitha too. Octane destroys the Spire structure, Mesmerize, in order to free her from their control.
- Octane and Tabitha are then travelling through Progenitor Swamp Lands encountering Osiris and Horus on their way.
- They eventually reach The Gateway in the middle of the Swamp Lands and trigger it in hope it takes them back home.
Attack on Ashrock, The Phobos Heist
- Octane and Tabitha return to Ashrock from Progenitor's Continuum seeing the Spire readying for launch to Phobos station. Ashrock is also being overrun by Raiders equipped with Xeno technology, apparently gathered in Invaders of the Wasteland event.
- While attempting a stealth approach, they run into Volatile and Castigator, but remain undetected by Imperials or Raiders.
- They eventually get discovered by Abel, who starts Abel's Gambit in order to stop them.
- The duo is discovered by Yurich eventually. In order to defeat Halcyon, they suggest to board his ship heading to Phobos. Yurich agrees, but to do so, they must shut down Annihilatron, the Raider siege device set to conquer the Spire.
- Tabitha and Octane successfully board the transport to Phobos, but are discovered during the flight. In an attempt to avoid being cornered on the transport, they leave the ship via escape pods, but are intercepted by Octane's Helios. They are discovered by Halcyon shortly after, who attacks them with The Intrepid.
- Octane tries to hack the Phobos's defense systems but fails. The duo has no choice but to battle the Phobos Station itself.
Eden Breached, Nexus of Eden
- Halcyon, against all odds defeated at Phobos Station, retreats to Eden, the Imperial heavily defended capital to plan a counterattack, but finds out the city's been infilitrated by Progenitors. Together with Erath he faces Hexertia.
- When facing Soulstalker, Halcyon orders Erath to use devastating weaponry (later revealed as the Nexus Arc Cannon), who reluctantly complies. As a result, many Eden civilians die.
- While fighting Uruk the Supreme that just descended from the sky, Halcyon admits that the Progenitors may be attracted to the 'power beneath the city streets' of some sort (later revealed to be the Nexus). Progenitors try to invade Eden's communication center, killing Erath in process, but are ultimately defeated.
- After repairing the damage dealt to Eden by Progenitors, Halcyon discovers a Xeno attack on the city led by Krellus. Halcyon intends to use The Intrepid against the Xeno, but he has to take down Zorum, a Xeno anti-air mech, first.
- To take down the Xeno swarm, Halcyon orders The Intrepid to attack Aerunor, supposed Xeno coordination center.
- With the Xeno in disarray, Halcyon leaves the city and moves towards the Valhalla Station where the attack of the Forsaken Raiders is reported. Cassius, leading the cleanup operation, discovers that Krellus is harvesting the Nexus's energy for the Conduit. He manages to overcome Krellus's defenses and supposedly to apprehend him.
Alpha Infection, Typhons Destruction
- Gore Typhon, having developed more aggressive Bloodthirsty virus that consumes its victims much faster than usual, attacks Alpha Island inhabited by Righteous. Empress deploys Faith Welder in defense and asks Constantine to provide backup.
- With Faith Welder destroyed, Bloodthirsty continue to slaughter Righteous warriors and workers on Alpha Island. Righteous Council agrees to send Beta Force Backup to the island. Gore Typhon orders his swarm to destroy Loader Bot.
- Empress finds out she is infected, too, and that Gore Typhon can access her mind through the virus. Constantine tells her about the cure, which forces Typhon to attack and destroy The Reckoning.
- Tabitha and Octane, apparently travelling nearby, detect a distress call from the invaded Alpha Island from Empress. Shortly after they are attacked by Typhon's Hatred and later Typhon's Malice emerging from the ocean.
- The duo is aided by Yurich. All the parties eventually come up with a plan to combine the power of Imperial's Phobos Station, Righteous's The Reckoning and Raider's Annihilatron against Typhon, Lord of Blight. Octane reaches through the hole in Typhon's body to tear him apart from the inside, killing him.
Vaults of Valhalla
- Halcyon arrives to the Valhalla Station only to find it overrrun by Vlade, who has found the Deimos Engine (an unstable core of a scrapped twin-station to Phobos). While taking the base back, Halcyon faces Arctic Vitriol.
- Before reaching Vlade's Outpost (formerly Valhalla Station), Halcyon receives the status report from Cassius, who decyphered Krellus's actions at Eden Nexus as a summon for the Xeno Armada.
- Halcyon re-captures the outpost only to be greeted by Vlade, who explains that the Sulfuris pits made the Forsaken Raiders strong enough to dominate the Bloodthirsty residing there, and in order to "make Acheron strong", he intends to use Deimos Despoiler to spread the acidic nature of Sulfuris all over Acheron.
Storms over Avalon
- Tabitha and Octane arrive on Acheron's moon, Lethe, in search for Halcyon's Avalon base. They are discovered shortly after finding the base, but not before they find out that Halcyon is developing a new weapon against the incoming Xeno Armada called the Excalibur, apparently weaponized version of Krellus's Conduit. Halcyon deploys Lunar Tank in an attempt to stop them.
- Cassius the Stalwart attempts to further delay the duo until Halcyon prepares the Excalibur, but fails. Octane ultimately faces Halcyon with Excalibur.
Sons of the Fallen
- Empress is sent by the Righteous Council to investigate the contact loss with the crew guarding Typhon's corpse. She encounters a few survivors led by Gialdrea fighting off Undying Wrath.
- Shortly after, Empress finds out that the survivors are actually heretics of the Nephilim faction, and faces the Nephilim Eos responsible for jamming her communications.
- Upon reestabilishing the communication with the Council, its member Torra explains the Nephilim's history. One of the fallen Sentinels, Semyaza Resurrected, is summoned onto Typhon's corpse, and Empress prepares to fight him.
- Tabitha and Octane with the support of Daedalus's Artemis station intercept the incoming Xeno Armada in deep space. The massive fleet seems to be hibernating, but the sentry ship of Kaszatah detects them and attempts to alert the rest of the ships.
- With Kaszatah dispatched, the Xeno Armada stays silent. The duo breaks into the Arkship to gather more info.