The Chief, Arbiter and Guilty Spark discover that the Ark is constructing another Halo to replace the one that the Chief previously destroyed. The Chief decides to activate this Halo; the ringworld would eliminate the Flood infestation on the Ark while sparing the galaxy at large from destruction. To activate the ring, the Chief rescues Cortana, who has the Activation Index of the destroyed Halo, from "High Charity" and destroys the city. Arriving on the new Halo, Cortana warns that Gravemind is trying to rebuild itself on the ring. The Chief, Arbiter, and Johnson travel to Halo's control room to activate the ring. Guilty Spark explains that because the ring is not yet complete, a premature activation will destroy it and the Ark. When Johnson ignores his warning, Guilty Spark fatally wounds him to protect "his" ring. Although the Chief destroys Guilty Spark, Johnson soon dies of his injuries. Chief activates the ring, and escapes the ring's self-destruction on the UNSC frigate "Forward Unto Dawn". However, the force of Halo's blast causes the slipspace portal to collapse, resulting in only the front half of "Forward Unto Dawn", carrying the Arbiter, making it back to Earth.