After landing on Onyx, the two of them linked up with Kurt, Mendez, and the surviving SPARTAN-III's, and later Blue Team. They combated numerous Covenant and Sentinel forces before taking refuge in the Shield World accessible at the center of the planet. To ensure no one else would pass through, Kurt-051 stayed behind and detonated two FERNIS nuclear warheads, destroying Onyx. After the war ended, UNSC forces would recon the debris field and discover a small slipspace bubble. After determining how to communicate with those outside, the group on the inside was able to tell them they would bring the planet back into real space. After doing that, Halsey was arrested for war crimes.