Changes

Following the attempt of [[Magnus the Red]] to warn the [[Emperor]] of [[Horus]]'s treachery, catastrophe struck [[Terra]]. Magnus's psychic warning breached the wards the Emperor had placed around the [[Imperial Palace]], causing the [[Golden Throne]], a device intended to allow [[human]] travel within the [[Webway]], to malfunction. As the Golden Throne broke down, the [[Webway Portal]] deep within the Imperial Palace became breached. Floods of [[daemon]]s rushed through this breach, and the Emperor dispatched despatched the [[Custodes]] and [[Sisters of Silence]] to hold the line and prevent Terra from being overrun. As the Custodes and Silent Sisterhood fought back immense Daemonic hordes, the Emperor sat upon the Golden Throne in a desperate attempt to stabilize stabilise the Webway Portal. Even the Emperor's psychic might was tested in this endeavorendeavour, and He became visibly exerted.{{Fn|2}} The war within the Webway forced the Emperor's entire attention, leaving the waging of the simultaneous [[Horus Heresy]] to [[Malcador (Character)|Malcador]] and [[Rogal Dorn]]. Malcador was the only one allowed to regularly visit with the Emperor.{{Fn|1}}

Soon enough, the war within the webway Webway fell into a pattern. The Custodians established a series of blockades across the tunnels within the webwayWebway. Behind these defended areas, the [[Mechanicum]] workers were repairing the damaged sections of tunnel and sealing the rifts to prevent more daemons from getting inside the webwayWebway. In front of the blockades, the Custodians and Sisters launched lightning-fast counter-attacks to keep the daemonic horde off-balance and prevent them massing in strength. Slowly, but surely, the Imperial forces were pushing the blockades forward as the pressure from the daemonic attacks waned. Nevertheless, some daemon assaults did manage to break through the Imperial defences and on those rare occasions the attackers wreaked havoc on the Imperial workers. More than once the daemonic entities were able to fight their way to the warp-gate of the Golden Throne. Desperate fighting ensued as the Custodians and Sisters doubled their efforts to throw back the daemons and prevent them surging through the warp-gate and into the Imperial Dungeon beyond.{{Fn|1}}

As the war raged on, new troops appeared amongst the hordes of daemons attacking the Imperial forces. The powers of [[Chaos]] sent foully corrupted [[Chaos Space Marines]], [[Traitor Titan Legions|Titans]] and other war machines into the webway Webway to try and force a victory. Mighty [[Greater Daemon]]s including [[Bloodthirster]]s joined the battle as well. The sanctity of the Imperial Palace, the fate of the Imperium and the very life of the Emperor depended on the Custodian Guard and the Sisters of Silence. If they couldn't defeat the daemonic horde and its corrupted allies then Humanity was surely doomed.{{Fn|1}}

The war within the Webway was waged for the next five years. Imperial forces were centered centred around the abandoned [[Eldar]] city of [[Calastar]], known as the Impossible City, defending the Webway tunnels constructed by the Mechanicum and held together by the Emperor upon the Golden Throne. The Custodes were reduced by 90% and the Sisters suffered greatly as well. Two of the three commanding Custodes Tribunes were killed, leaving [[Ra Endymion]] as the primary Imperial officer. The Impossible City itself soon came under threat as a formidable new foe, [[Drach'nyen]], appeared among the Daemonic hordes. Faced with this, the Custodes [[Diocletian Coros]] was charged with securing reinforcements from Terra. Due to the secrecy of the project, the scarce resources available because of the ongoing Heresy, the maddening effect of Chaos, and the questionable loyalty of the [[Legiones Astartes]] only the doomed prisoners of [[House Vyridion]], the crippled [[Blood Angel]] [[Dominion Zephon]], and Mechanicum [[Servitor]]s and [[Skitarii]] were provided. A Mechanicum [[Dominus]] known as [[Hieronyma#The Archimandrite|The Archimandrite]] was charged with leading them in the final defense of Calastar. Meanwhile, the Emperor charged the Sisters of Silence with the '''Unspoken Sanction''', and the [[League of Black Ships|Black Ships]] worked at a hurried pace to gather [[Psyker]]s across the galaxyGalaxy.{{Fn|3}}

In the siege of Calastar, the Custodes-led forces held back countless Chaotic hordes but the walls of the city were shattered by [[Warhound Titan]]s of the [[Legio Audax]]. Brutal fighting for Calastar raged for weeks on end, the Custodes and Sisters not having a moments moment's rest. As Daemonic, Traitor Legionnaire, and Chaos Titan hordes swarmed into Calastar, The Archimandrite ordered a general retreat of her forces. They intended to abandon to the Custodes and Sisters and instead secure the Webway route to [[Mars]] and reclaim their sacred homeland. This desperate treachery did not save The Archimandrite who was possessed by Drach'nyen, her gigantic mechanical form being used to attack the retreating Imperials. Calastar fell and the Chaos forces drove the Imperials all the way back to the Webway Gate leading to Terra itself.