The Tonnant was a DropShip belonging to the mercenary unit Grandin's Crusaders notable for its role in assisting in the escape of Internal Security Force Director Ninyu Kerai-Indrahar from Dieron following the Word of Blake invasion in 3068. Grandin's Crusaders were in the employment of Interstellar Expeditions at the time, and IE loaned the mercenaries to the Draconis Combine Mustered Soldiery to aid in the rescue of the head of the ISF, who had been badly injured. The Crusaders dropped into the Scales of the Dragonet Mountains in April 3068 to meet up with the convoy transporting Kerai-Indrahar to a secure DropPort via a secret route. The Crusaders arrived to discover that the apparently secret route wasn't as secret as it had been described to be, and elements of the Eighth Militia Divison were in pursuit of the convoy. The Crusaders' 'Mech forces fought a series of small actions to delay the Eighth while the Crusders' infantry elements prepared a position at a narrow choke point on the route; bolstered by a squad of Kage battle armor, the infantry was able to throw out enough firepower to dissuade the Eighth's forces from trying the pass, buying Kerai-Indrahar's convoy time to escape.
Grandin's Crusaders fell back in an orderly fashion as the convoy closed on the DropPort, skirmishing with the Blakist forces until Kerai-Indrahar boarded a waiting Condor-class DropShip. The Blakists attempted to intercept Kerai-Indrahar's ship off-world, leading to Grandin engaging the Blakist forces with the Tonnant untli the Blakist fighters had been driven off; the DCMS subsequently rewarded the Crusaders for "volunteering" to engage the Blakists a second time - albeit at the urging of their IE liaison - by supplying them with a range of military equipment.
In February 3069 the Tonnant was involved in a covert operation in the Thraxa system on behalf of the Magistracy Intelligence Ministry. The Crusaders had been running relief convoys into the Rim Commonality on behalf of a group called the Coterie when they were routed to the Gambilon system. At the urging of IE once more, the Crusaders accepted a contract that took them to the nadir jump point in the Thraxa system, where they were met by three Mark VII Landing Craft operated by Canopian intelligence agents. The Tonnant escorted the three craft to Thraxa, where two of the elite teams served as a distraction for the local militia and mercenary forces whilst the third landing craft successfully inserted its personnel via HALO drop. The Tonnant took some minor damage during the operation, but the generous contract payment more than covered the cost of the repair work, which was performed at an IE yard. During the operation Grandin identified one of the mercenary units as a unit impressed into service with the Word of Blake via the company-store trap, but withheld that information; Grandin subsequently learned that the entire operation had itself been a distraction, covering for an operation aimed at toppling the local government on Thraxa, which was collaborating with the Blakists. The intelligence report provided to IE by the Cursaders was one of the first signs available that there was some form of resistance to the Blakist occupation ongoing within the Magistracy of Canopus. The Tonnant was back in service with the Crusaders in December 3069 after her repairs were completed.
- Total Chaos, p. 58, "Aftermath"
- Total Chaos, p. 76, "Aftermath"
- Total Chaos, p. 82, "Living Dead Men"