Just as the new edition of Warhammer: The Horus Heresy advances inexorably toward release, so too did the shadow of Horus’ rebellion loom ever larger over humanity’s Throneworld. After the devastation of the Drop Site Massacre, Traitor forces surged out across the stars. It would take almost a decade for the Warmaster’s fleet to arrive above Terra, but the war for the Sol System began much sooner – not with a bang, but with a whisper…
First to strike were the Alpha Legion, charged by Horus to sow discord and confusion throughout the Imperium’s nerve centre. Sleeper cells planted years before the Heresy awoke and unleashed sabotage attacks, killing millions and drawing Terra’s eyes away from the Primarch Alpharius’ true prize – Pluto.
Home to the Sol System’s primary surveillance stations, Pluto and its moons were a vital part of Rogal Dorn’s strategy for the upcoming war. Alpharius attacked it in person, leading his Headhunters in a spearhead attack to silence the dwarf planet’s astropathic choir and plunge Terra’s intelligence networks into darkness.
This crippling gambit would have succeeded, but for a brilliant slingshot maneuver around Sol’s gravity wells that catapulted the Phalanx – and Dorn himself, accompanied by his Huscarl Terminators – to the edge of the system. There, the brother Primarchs clashed sword-to-spear, and Rogal Dorn wordlessly struck down Alpharius* in a bitter duel.
Although the Alpha Legion’s attack had been blunted, all this victory bought was time. The Imperial Fists spent years turning the moons of Pluto into mighty battle fortresses, digging in to await the inevitable arrival of the main Traitor armada. After years of bloody struggle and desperate preparation, the Warmaster’s attack began.
Two enormous fleets surged through the warp gates around Pluto and Uranus – opposed by Sigismund and his fanatical Templars. At the battle’s apex, the Eternal Crusader broadcast the fall of Pluto and began to retreat his ships towards Terra, only to enact an unthinkable plan when the Sons of Horus gave chase.
A data-jinn concocted by the Mechanicum wormed its way through Pluto’s moons, detonating apocalyptic caches of fuel and ammunition. One by one, the moons exploded, evaporating hundreds of tightly-manoeuvring Traitor ships in seconds – right as the Imperial Fists fleet turned around to charge back into the fray. With confusion on their side, the defenders claimed a bloody toll against the Warmaster’s overwhelming numbers, but were eventually forced to withdraw.
Splinter fleets clashed throughout the system as an armada of Sons of Horus, Word Bearers, and Thousand Sons soared over the galactic plane to attack Loyalist defences from above. A fast-moving force of White Scars intercepted them in countless battles among the stars, but even they could do little to prevent a direct attack on Jupiter by Perturabo himself, fresh from his victory at Uranus.
On the surface of Venus, Azhek Ahriman completed a profane ritual to open a tear in the fabric of reality so large it blocked out the sun, through which hordes of vile daemons and over ten thousand Traitor ships emerged. Angron, Fulgrim, and Horus rode their flagships to the very heart of Terra’s orbital defences on Luna, smashing aside the defending fleet and scattering the Loyalists’ final line of defence.
Ultimately, the defence of the Sol System was abandoned, with surviving Loyalist vessels retreating to the system’s edge to avoid destruction. Dorn’s plan to resist until Roboute Guilliman’s reinforcements could arrive had failed, and all that remained was the assault on Horus’ ultimate prize – the Imperial Palace.
Whose side will you be on as the Horus Heresy reaches its climax? Discover your Legion at the Horus Heresy website, and join us on Saturday the 7th of May (that’s just next week!) for a full day of incredible reveals at Warhammer Fest Online.
* Or did he? It’s hard to tell with Alpharius involved.