When his fleet emerged from the Warp they immediately besieged the Tau Sept of Kel'shan but hadn't realised that one hundred and fifty years had passed and the Damocles Crusade had already come to an end. Shortly after Hive Fleet Gorgon descended upon Kel'shan and, faced with a common enemy, Crask and Kor'o Valroth agreed to a truce. Together their fleets turned on the hive fleet destroying nearly all of its Bio-ships. Gorgon, unique for its ability to rapidly evolve its bioforms, was unable to adapt quickly enough to the disparate nature of the Tau and Imperial Guard forces combined and, at the Battle of Worldspine Ridge, the forces of Gorgon were finally defeated. Valroth's truce with the Imperium also ended shortly after. The Imperial forces, too depleted to continue their mission against the Tau, were allowed to withdraw from Tau Space and were given honours for their assistance.