Author's Note: And the second chapter is out! Note that parts of the 1981 section are paraphrased from the books, although I tried to avoid directly copy-pasting. As always, Warhammer 40,000 and the Harry Potter universes belong to Games Workshop and JK Rowling respectively.

IMPERIAL STANDARD DATE: 435.M42
GREGORIAN CALENDAR DATE: 41435

The great starship Ananke plied the psychic seas of the Immaterium, gellar field flaring but holding firm against the onslaught of the warp's corrupting power. Fifteen kilometers of cathedral spires, prison cells and weapons batteries, the Ananke was no ordinary Imperial warship or transport- but rather a member of that infamous cadre of heavily-armed psyker containment vessels known as the Black Ships. Recently, however, the Ananke had come under new management.

The ivory symbol of the Imperial Inquisition glittered on the ship's flank, lit by floodlights arranged around it and the unearthly light of the warp. Currently, the vessel served as the flagship of one Inquisitor Charles Frederique De Fay of the Ordo Chronos- a shadowy order of the Inquisition dedicated to the study and weaponization of time itself.

The agents who formed this group were eccentric people belonging to more radical sects of the Inquisition, men and women who were willing to use some highly questionable methods and technologies in their quest to safeguard the Imperium from threats beyond the normal space-time continuum, and De Fay was no exception.

The Ananke's main cargo bay housed a strange and arcane contraption, a psychic focus device linked to the hundreds of imprisoned psykers within the Black Ship's brig. The mechanism acted as Charles' eye into the past, and a method of influencing events there via controlled application of psy-sorcery. If he wanted, he might be able to use the machine to open a one-way realspace rift to a previous time- but the power drain that would create would kill off the other psykers hooked up to it, forcing the Inquisitor to trawl the galaxy for replacements.

De Fay was on the command deck of his flagship when the astropathic transmission reached him. It was a short, simple message, requiring the highest inquisitorial clearance to access. "Arvellia has fallen," it said. "The gate is lost." "Throne damn it!" cried the inquisitor, burning the parchment the message had been printed on to ash. He stormed off to his office, his greatcoat billowing behind him. Upon reaching there, he slumped down on his chair and opened up his workstation cogitator to review the battle report in greater detail.

…..

After-Action Report 10349548103999586

Fall of Hive World Arvellia

Warning, this information is classified code Vermillion. Unauthorized access will result in termination.

++Glory to the eternal God Emperor, in whose name we hold our vigil++

At 0400 hours local time, twenty (20) combat starships affiliated with a warband of Chaos Undivided led by one "Archon Rek'zvar" exit warpspace four light-seconds from Hive World Arvelia. Fleet composition unconfirmed, estimated to include ten vessels of "Iconoclast" (Destroyer) classification, six vessels of "Murder" (Cruiser) classification, three vessels of "Styx" (Heavy Cruiser) classification, and one Grand Cruiser or battleship of unknown classification. XI Sector Patrol Group, consisting of the vessels "Golden Bulwark" (Avenger-Class Grand Cruiser) "Gloria Imperator" (Lunar-Class Cruiser), "Dominus Sol" (Sword Class Frigate), and six (6) sub-light defensive gunboats intercept the incoming foe.

At 0430 hours local time, an inquisitorial monitoring corvette arrives on scene, and conceals itself behind Arvelia's moon. Much of the data within this report was gathered by this vessel.

At 0500 hours local time, Arvelia Planetary Defence Command reports multiple heretical uprisings within the outlying hives.

Note: These insurrections were likely pre-planned and timed to occur at the same time as the arrival of the Chaos fleet. Investigation pending after world liberation.

At 0600 hours local time, the anti-orbital batteries on Arvelia's surface are sabotaged. PDF forces in several hives have been routed, and Arvelia Command orders surviving units to retreat to the Central Hive in preparation for planetary invasion.

At 0800 hours local time, the confrontation in space ends with the complete obliteration of XI SPG. Five (5) heretical Destroyers, and three (3) heretical Cruisers are also destroyed in turn. The Chaos fleet enters low orbit and begins orbital bombardment of defensive batteries, which are unable to retaliate.

At 0820 hours local time, the Chaos invasion force makes planetfall four (4) kilometers outside the Central Hive, and lays siege to it with mobile artillery pieces. The PDF responds with counter-battery fire, and an artillery duel ensues.

At 1700 hours local time the next day, shellfire breaks the Central Hive's void shield. The Archon launches an infantry offensive at the fortified perimeter of the hive, but is repulsed temporarily by fire from the defenders and their surviving artillery.

At 1800 hours local time on day two (2) , four hundred (400) armored including ten (10) super-heavy vehicles assault and breach the main gate to the hive.

At 1930 hours local time on day two (2), Battalions I through V of the PDF Armored Corps, comprising of two hundred fifty (250) "Leman Russ" Main Battle Tanks of assorted pattern and one "Baneblade" Super-heavy Tank launch a counterattack through the ruins, and a secondary entrance from the hive. They encircle and destroy at least two hundred (200) of the Archenemy's tanks.

At 2020 hours local time on day two (2), the PDF armored thrust is destroyed completely and Chaos armor and infantry breaches the hive defences.

At 2257 hours local time on day two (2), all transmissions from Arvellia Planetary Defence Command cease. Planet designated as under the control of Chaos Undivided.

At 2345 hours local time on day two (2), Inquisitorial storm-troopers assigned to guard the compound containing the artefact report an incoming force of traitor Astartes. Vox contact between them and the Inquisitorial corvette was lost shortly after.

At 0000 hours local time on day three (3), a major psychic surge is detected from the location of the compound. Surge consistent with artefact activation.

Note: How the door was opened without the key is unknown. Investigation pending after world liberation.

At 0315 hours local time on day three (3), Inquisitorial monitoring corvette is discovered by enemy patrol vessels and forced to disengage.

Report end.

This message will self-expunge in 5 seconds

Charles groaned and let the message self-destruct, before reaching for a nearby bottle of amasec and pouring himself a glass. "That heretic knew what he was looking for when he attacked Arvellia, and he used it seemingly successfully. I must figure out what he's doing." He drank, and calmed down somewhat, standing up and heading off to the Black Ship's hangar bay and the contraption it housed. A team of tech-priests met him at the machine, mumbling binaric interactions as they connected the Inquisitor to the focus device via interface ports implanted in his skin. "All right, let's see what he did to the timeline." said Charles, closing his eyes and letting the warp flow through him and providing him with a vision of centuries past. For a second, he was overwhelmed by the flow of information, but he was no newcomer to this sorcery, and quickly brought it under control. "Ah, tainting a child? Talk about a slow burn! Well, I will humor him for a while. Since I'm not dead and the Imperium still exists, he hasn't done any harm to the timeline yet."

…

IMPERIAL STANDARD DATE: 981.M2

GREGORIAN CALENDAR DATE: 1981

''Lilly, it's Voldemort! Get Harry and run!" A flash of green light lit up the night in the quiet, sleepy village of Godrick's Hollow. A figure robed in black advanced through a house, leaving a man's corpse in his wake. He moved swiftly from room to room, finally alighting upon a bedroom, which contained a woman, who was shielding a baby in a crib. "Step aside, silly girl." hissed the man, sounding rather disinterested. "No! Take me, not him!" replied the woman. Another flash of green light filled the house. Pushing the mother's body aside, The cloaked man turned his wand on the baby in the crib. "Avada Kedavra!" The spell slammed into a barrier of golden light inches away from the child, and the house collapsed.

…

A nondescript man in a nondescript room looked up from his nondescript work. "Huh, that's weird."

IMPERIAL STANDARD DATE: 435.M42

GREGORIAN CALENDAR DATE: 41435

"Your move, heretic." The inquisitor grinned, his plan had succeeded for now.