An original novel set in the Halo universe--based on the New York Times bestselling video game series October 2559. With the galaxy in the suffocating grip of a renegade artificial intelligence, another perilous threat has quietly emerged in the shadows: the Keepers of the One Freedom, a fanatical and merciless Covenant splinter group, has made its way beyond the borders of the galaxy to an ancient Forerunner installation known...