When described in the future the words "lightning raid" would often be tossed about regarding the Bagalog raid on Incleon. In the strategic sense it almost was but the attack itself was almost a Terran week of maneuvering in the outer system, ships trading a few volleys before disengaging, and furious plotting by the minds leading the polar opposite forces. Where the defenders were physically infected with technological pathogens the attackers were ruggedly built ships with clean angles. At the somewhat center of their elements lay a Light Cruiser and its direct Escorts: Lord Explorator Ulshavon had taken to the field personally. As bait, and for the possible rewards.
Incleon was once a world with a heavy Mechanicus presence. Similar to Lexicalum but oh so much more the nascent Forge World had been built in the satellite of a lesser planet. When it had fallen to the taint within the lessers had been quickly and efficiently subjugated and turned to the purpose of supplying the forges with materials. A great deal had been sacrificed to augment the eight monitors the previous administration had maintained with something akin to the Obliterator virus. The gremlin, the glitch, the untraceable fault that was only revealed by another or after time had passed given form and substance by the whims of the Warp.
Safeguarded from depredation by the marauding greenskins by stationary defenses as well as the mobile garrison, the newly formed sect of the Dark Mechanicus began to cautiously delve into the mysteries of the Warp. Of course, one world can not feed the hunger of such pursuits and so the cults nearby were courted. They would arrive with holds of slaves and materials to be exchanged for repairs and new hulls. New and better ships such as the Reaver (known to the Crusade simply as the Cult Raider) made their way onto the catalogues as business boomed. The misguided Loyalists of Calavar might be exterminating the nearest cults but did not go so far as to worry the Dark Forge. Indeed, their overextension resulted in a great deal of profit when a band of mercenaries were hired to strike while the battle fleets were away, acquiring most of the "Shelter" schematics and some of the "Savior". Finishing the latter was simple due to the proliferation it was already seeing but the former required a more... Delicate touch. Or hamfisted depending on what one believed.
And then the warp wake of the inbound Bagalog flotilla was detected. It was too small to conquer Incleon so it clearly was not a full attack but instead a raid. Assets were doled out accordingly to prevent an ironic repeat of what was done to the Loyalists.
Following the lengthy period of maneuver the Lord Explorator finally committed his personal squadron. Just three ships perhaps, but they were no "mere three ships". His artifice was plain to see on all of them, from the completely rebuilt combat transport to the sensors, guns, and shields of the retinue.
Even so, the four ships they faced were touched by Chaos, and more conventional defenders lay behind them. Carrying Lances instead of Warp drives, that carried contagion and scrap code along with searing damage, the monitors smoothly bent to converge on the foolish overextension of the most dangerous and valuable ship in the raiders flotilla. Death and destruction were dealt as the two forces passed one another, and damage was tallied as fires and masses of animated hull and armor plating were combated by crews. The monitors came out distinctly worse than their opposites, two being outright destroyed and one struggling to regenerate, but the Explorator had not come out unscathed. Still. The monitors were now being pounced, somewhat, on by the rest of the Bagalog ships and were no longer a concern. Instead, the remainder of the Incleon forces were looking on as the battered but resolute trio swept onward past the wrecks and expanding debris clouds (hyper capacitors could be quite volatile when suddenly heavily damaged with a full charge) and toward them. While they didn't quite scatter it was enough for them to put in only a modicum of effort at dissuading the advancing Explorator, content with coming to grips with the unaugmented vessels behind them.
Curiously, the Explorator's flagship kept cycling its torpedo tubes without firing any weapons. The reason was made apparent as flashes of searing light and radiation broke the voids over the nearest section of docks: a smaller projectile under the same force moved faster.
As matter annihilation reactions marched over a handful of construction slips and the frames inside them the defense platforms spat rebukes at the impudent aggressor, forcing the Explorator to break off with a mission essentially accomplished. It was minor damage to the facilities of Incleon but it would be enough to satisfy Calavar. The attack also gave cover to stealth insertions of a boarding team onto one of the orbital platforms, set in motion during the maneuvering of the days past. Augmented memetic noosphere filters and enhanced immuno-sequestration defenses allowed the strike force to cut into a disturbingly life like cogitator and transmit a great deal of raw data to the Explorator before scrubbing themselves and a number of security forces with thermonuclear devices.
[Lord Explorator Ulshavon joined the promised raid, allowing minor damage to be done to Incleon's shipbuilding capacity and killing a number of ships. The regular Bagalog vessels fared poorly against the corruptive touch of the systems guardians, losing two of their number through infection and damage to finish two wounded enemies.
Ulshavon would only share the recovered data after thoroughly scrubbing any hint of Warp taint from it. Most of it would turn out to be junk data of interest to the Intelligence agencies alone for insights into the daily operations of the enemy, but a few tidbits were of use. The development and deployment of Daemon "engines" of Shelter armor for one. Advanced warning of coming classes of warships among the cults for another.]