"A nest of vipers; a haunt of outlaws; a lair of thieves. That is what many traders and the people of nearby settlements said of the Stones of Cavadi, a large asteroid field. Located as far from the tumultuous edge of the Great Rift as any region within the Nachmund Gauntlet, it had become a place of relative safety. Only the strongest and meanest personalities succeeded in securing a sanctuary there, and they fought tooth and nail to keep it. A corsair and renegade society emerged within the asteroids, with a dozen and more races represented amongst the populace. While a semblance of order was maintained between the groups of raiders, they all attacked passing shipping, nearby worlds, and places further afield. Pirates from different alien species even worked together against larger and more dangerous prey. Yet when they struck and plundered a vessel belonging to valued agents of the Ordo Xenos Inquisitor Kirs Drova, the ruthless woman decided to see the Stones of Cavadi rendered silent.
For this, she enlisted the aid of a strike force from the Wrathhost Chapter. Initially, the Space Marines' approach relied on two primary tactics. The first was to attack with remorseless ferocity, allowing their foes no time or space to manoeuvre; the second was to attack only one pirate lord at a time. The latter relied on one assumption: that the various leaders – cowardly and selfish as they surely were – would not risk their lives fighting Space Marines to defend one another. But it did not work out that way. The pirates and raiders fought with a cohesion and solidarity that surprised the Adeptus Astartes and Inquisitor Drova alike. What started as a swift, decisive campaign was drawn out into a gruelling guerrilla war. The Wrathhost lost the Gladius-class escorts Coiled Viper and Biting Jackal, while the strike cruiser Mistral suffered considerable damage.
Inquisitor Drova requisitioned detachments of the Imperial Navy, which not only provided support to the Wrathhost ships fighting in the asteroid field but also blockaded the region. No pirate vessel that dared to attempt an escape from the wrath of the Imperium would succeed, Drova declared. As each asteroid held by the pirates was declared void of foes, Imperial Navy armsmen occupied it and took control. Slowly but surely, those enemies of the Wrathhost that had yet to be destroyed had fewer and fewer places left to run. Some fought to the end against the Space Marines and supporting armsmen, their lives brutally stamped out. When each pirate holding was secured, Drova's agents stripped it bare. Weapons, equipment, books, vehicles, esoteric artefacts – all fell into her hands. Much intelligence was yielded from this, enabling Imperial forces to discover the most hidden of the enemy bases. Pirate forces slipped away again and again, retreating to secret supply stores or the strongholds of allies, but any that tried to escape the Stones were intercepted by prowling Imperial destroyers.
Eventually, no pirate strongholds remained. Thousands of raiders were dead and hundreds more were in the cells of Inquisitor Drova's dungeons. When the Wrathhost thought their mission in the Stones of Cavadi complete, however, a single alien ship broke away from an asteroid previously thought to have been uninhabited. The Gladius-class escort Leaping Pronghorn pursued. After an hour of weaving through asteroids, the craft was within close enough range to unleash boarding craft. Battle-brothers stormed the alien vessel, killing and capturing all they encountered. They met fierce resistance, from Human, Kroot, Demiurg, Tarellian and Nicassar crew, some declaring they would never let the 'Gue'ron'sha' reach their leader. When the Space Marines finally reached the vessel's bridge, they found a high-ranking T'au Water caste envoy. This was why the pirates had fought together so effectively, the Adeptus Astartes realised; they had been bonded by the words of this T'au. The creature spoke to them in perfect Imperial Gothic, congratulated them for their victory over his forces in the Stones of Cavadi, and surrendered. The Wrathhost had never heard of any T'au being encountered beyond the xenos' empire in the Eastern Fringe. They handed the alien over to Inquisitor Drova's custody."