Bear, Greg, 1951-2022. Forerunner saga #3

Halo series.

"A Tom Doherty Associates book."

Facing the imminent collapse of their civilization, the Librarian and the Ur-Didact reveal what they know about the relationship between the long-vanished Precursors and the Flood. Facing the consequences of a mythic tragedy, one of them must now commit the greatest atrocity of all time -- to prevent an insane evil from dominating the entire universe

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