Guided by his visions, John takes Halsey and Cortana back to where it all began, looking for answers from his past. With Soren along for protection, Kwan goes in search of an army. Meanwhile, John's behavior inspires another Spartan to begin a journey of self-discovery. And Miranda discovers a possible link between the artifact and something much larger.

Survivors from the battle return to Reach. John confronts Dr. Halsey, and the lies of his past.