"The Covenant glassed my home," Cortana says. Insofar as she ever had one, anyway. Maybe Reach hadn't been home so much as the idea of home--familiarity, stability, security. All turned to ash and glass in the Covenant's endless, misguided holy war.

The thought of it calls its ghost into being, a bulkhead melting away to an impressionist sketch of high mountains with vast pine forests, all burning. Even a phantasmal holocaust carries a whiff of burning resin across to them, and Cortana catches herself quickly. She never smelled Reach burning, only watched through the Pillar of Autumn's sensors.

With a conscious act of will this time, she thinks of construction specifications. Marathon-class heavy cruiser. Two solid meters of titanium-A armor plate between them and any memories. The bulkhead snaps back into existence, for the moment as real and substantial as they are.

"Do me a favor." Cortana reaches up to the back of her body's skull, pulling out an AI datachip. "Slot this into your helmet."