Here comes the bad news for the Green Lanterns Corps. The Green Lantern Corps was plunged into an intergalactic was when renegade Corps member Sinestro created his own parliamentary force. Using fear as a power source, the universe's deadliest and most feared beings were selected to join the Sinestro Corps, including the Anti-Monitor, Superboy-Prime, Cyborg Superman and an all-new Parallax, who was now possessing the Green Lantern's most powerful member Kyle Rayner (Ion).
The double sized special by writer Geoff Johns and artist Ethan Van Sciver saw Sinestro muster his forces as yellow rings selected members from across the universe and brought them to Qward, a world deep in the anti-matter universe. Over the course of the eleven part epic (which continued in Green Lantern - 4th series - # 21 in September 2007 and Green Lantern Corps # 24, the conflict spread through the entire galaxy. The Guardians argued about the best course of action and Ganthet and Sayd left, opposing the group. The Guardians of the Universe rewrote their own code of laws, creating ten new laws - including the use of lethal force against the Sinestro Corps.
As many of Earth's heroes - including the Justice League of America and the Teen Titans - came to fight alongside the Green Lanterns, one of the Guardians was scarred trying to stop the Anti-Monitor, who himself was thrown into deep space by a crazed Superboy - Prime. Another Guardian gave up his life force to send Superboy Prime back into his home universe and, as the Sinestro Corps fled, Sinestro himself was defeated and arrested by Hal Jordan. Sinestro's plan wasn't to win the war, however, but to make the Guardians change their laws to allow their members to kill.
The series ended on an ominous note, with a final image of a giant black lantern on the anti-matter world of Qward, waiting for the rise of the Black Lanterns. The series proved to be another successful epic in the Green Lantern saga, one of DC's most popular titles since Geoff Johns revamp of the heroin 2002.
Collected in The Sinestro Corps War Vol. 1, The Sinestro Corps War and Absolute Sinestro Corps War.