The final installment in the New York Times bestselling series In the first Forerunner novel, rebellious young Forerunner Bornstellar Makes Eternal Lasting crosses the paths of two humans, and the long-life line of a great military leader... forever changing Bornstellar's destiny... and the fate of the entire galaxy. In the second, those two humans – Chakas and Riser – are captured by the Master Builder, misplaced during a furious battle in space, and find themselves on an inverted world where horizons rise into the sky, and where humans of all kinds are trapped in a perilous cycle of horror and neglect. They became both research animals and strategic pawns in a cosmic game whose madness knows no end – a game of ancient vengeance between the powers who seeded the galaxy with life, and the Forerunners who expect to inherit their sacred Mantle of duty to all living things. Now, the third book in this ground-breaking trilogy will reveal the ultimate purpose of this ancient game, challenging everything we thought we knew about the Forerunners.