Escaping the destruction via a fighter , the Chief and Cortana believe themselves the only survivors of the catastrophe .
The SPARTAN Master Chief and his artificial intelligence companion , Cortana , detonate the Pillar of Autumn 's engines , destroying Halo .
Escaping the destruction via a fighter , the Chief and Cortana believe themselves the only survivors of the catastrophe .
The SPARTAN Master Chief and his artificial intelligence companion , Cortana , detonate the Pillar of Autumn 's engines , destroying Halo .