When the Orbital was slated for destruction during the Idiran-Culture War it returned to Culture service and sent to evacuate the Eaters. The Eaters refused to board but Tsealsir was instructed not to leave until the last moment.
Horza boarded Tsealsir after escaping from the Eaters 43 standard hours before the Orbital's demolition. Horza feigned a serious fire and used Tsealsir's reaction to locate its brain. The Changer then destroyed the brain and commandeered the shuttle to Evanauth.