 The Covenant 's first appearance in the video games is in Halo : Combat Evolved ( 2001 ) , which picks up towards the end of The Fall of Reach . A detachment of Covenant follow the human vessel Pillar of Autumn from Reach to Halo , a ring @-@ shaped Forerunner relic that the Covenant believe sacred . Wary of accidentally damaging the ring , the Covenant are forced to fight the humans on foot , and accidentally release the Flood . The Flood , a virulent parasite that infests sentient life , attack human and Covenant alike and threaten to capture a Covenant cruiser to escape their prison on Halo . Meanwhile , the human " Spartan " supersoldier Master Chief detonates the Pillar of Autumn 's engines , destroying the ring and the Covenant armada . The novelization of the game , Halo : The Flood ( 2003 ) , describes additional events not seen in the game . In the novel First Strike , The Master Chief , survivors of the Autumn and surviving Spartans from Reach destroy a Covenant fleet they learn is preparing to strike Earth , and race home to warn of the impending attack . 
