Shadowstrike badly wanted to eliminate this threat but the Marine's mobility and grasp of strategy made them impossible to engage on the Tau's terms. In order to destroy them they would have to be brought to a time and place of the Tau's choosing. To this end Shadowstrike decided to employ the strategy of Kauyon – The Patient Hunter. In Kauyon a bait or false indication of weakness is used to draw enemy forces into an ambush. In order to lure the mighty Space Marines en masse the bait would have to be something of enormous value, something totally irresistible to Imperial command, and the location would have to be a place only the Space Marines could reach.
Only one bait would be sufficient to entice the Imperium into taking such a risk: Shadowstrike himself. In an intricate operation the Tau ensured that Imperial Intelligence would discover the location of Shadowstrike's command complex, codenamed Superiority. Located far behind the front lines and covered by the protective umbrella of the Tau Air Caste in air and space only a rapid orbital insertion could hope to succeed in breaching the base and killing Shadowstrike.
The bait was further sweetened by the arrival of Commanders Whitefire and Dawnstride at Superiority Complex. In a heated war council Marine captains warned of the risks of an orbital strike so far from friendly forces but High Command would hear none of it. They were desperate for a significant victory to demonstrate to their own superiors they had a grip on the situation. The spectre of a multitude of worlds lost to the Tau under Shadowstrike's command hung over them and motivated them to abandon all reason in securing his demise. Reluctantly the Space Wolves and Lamenters based on Tyranteous agreed to the strike.
The trap set, Shadowstrike's plan was disrupted by the last minute arrival of an Ethereal at the base on a surprise inspection. He was quickly escorted back to the landing pad and a shuttle called in to remove him from the impending conflict but before it could arrive the Marines struck.
Without warning drop pods screamed down from orbit, blazing through the sky in trails of fire. Closely behind followed the finest of the Lamenters, jumping out of Thunderhawks in the upper atmosphere and using their jump packs to control their fall. The suddenness and ferocity of such attacks had broken many armies throughout the galaxy but Shadowstrike had studied his enemies tactics and the Tau were ready and waiting. Even as the Marines made planetfall they took heavy incoming fire from carefully sited and concealed air defences and found themselves instantly surrounded by a force many times strong than they had expected.
In the open layout of the Tau base there was no place of respite from the overwhelming volume of fire directed at each contingent as they arrived. The Space Marines had some initial success in bringing down the Tau's Riptides – suits so large their positions had been identified from orbit and were the first targets of the Marines' wrath. But it was too little and the Marines suffered catastrophic casualties. A mechanised thrust which approached the base perimeter, somehow not detected by the Tau until it was too late, was able to make a stand but as soon as the Marines within the base had been eliminated the Tau turned their weaponry outwards and the tanks too were destroyed.
The Tau plan had been an overwhelming success and the attackers casualties had been enormous with the Tau's own losses minimal. Despite this Shadowstrike took little joy in the victory. Over many conflicts the Tau had learned to respect the Space Marines as skilled, honourable and worthy adversaries and the sight of so many great warriors slaughtered through the stupidity of commanders who would never themselves set foot on a battlefield was tragic. In a show of respect the bodies of the dead marines were returned to their Chapters so that they might be honoured in whatever way their battle brothers deemed fit.
This action did bring one unexpected ray of hope to the Imperium – the grainy imagery from a dead Space Wolve's helmet camera seemed to show a battle suit tentatively identified as Commander Whitefire being felled by a Krak missile in the closing moments of the battle. His fate was unknown but in a desperate effort to save his own neck it allowed Lord General Brooke to claim the attack had been at least partially successful in eliminating the Tau high command. This did little to endear him to the Space Marine chapters supporting his efforts who saw such a 'victory' as no compensation at all for so many dead.
It wasn't enough for General Brooke. By 0607.013M42 he was out of a job, replaced by General Montgomery by the Commissar-General of the sector, Lord Ferdinand Crowe. Crowe, who had arrived with the new sector government, had been content to sit back and watch events unfold. The latest catastrophe on Tyranteous made up his mind. In the same week that Brooke was moved to an "administrative role", Lord General Roover was "retired", and the general on the ground, who had fallen so completely for Shadowstrike's trap, Mikell Denham found himself courtmartialled and executed for dereliction of duty. General Cunningham, a veteran of Melberg and Tarsis, was called upon once more, finding himself again facing the tau in an almost impossible situation, with orders to hold the line.