Following his defeat in Green Lantern: Rebirth, the events of Green Lantern: Sinestro Corps Special #1 Sinestro retreats to the planet Qward in the antimatter universe.
As the Sinestro Corps spreads out to ambush Green Lanterns across the universe, Green Lantern vol. 4 #23 sees the Guardians deciding to rewrite their sacred text, the Book of Oa.