While on a crusade to liberate the reliquary world of Egottha in 990.M41, he received the general recall message which ordered the entire Chapter to return to their home world of Sotha. Concerned by the grave implications of such an order, he urged the captain and crew of the Xenophon to push the ship as hard as they could, for fear that they would arrive too late.
When the ship encountered a small vanguard Hive Fleet, Hornindal recognised the Tyranid threat for what it was, and correctly deduced that this was part of a new xenos invasion of the Imperium. This was later known to be the first wave of Hive Fleet Kraken to penetrate deep into Ultima Segmentum, far beyond previous estimates at that time.
Despite Hornindal's skilled leadership, the Xenophon was caught and boarded by Tyranid creatures. In the moments before it was destroyed, Hornindal recorded a message to be relayed by distress beacon, warning other ships of the danger to Sotha.