Issues in the crossover were written by each of the various series' writers: Geoff Johns, Tony Bedard, and Peter Tomasi respectively, and drawn by Doug Mahnke, Tyler Kirkham, and Fernando Pasarin.

The story arcs run was between March and June 2011, starting with a prologue in Green Lantern (vol.

While pursuing the renegade Guardian Krona, Hal Jordan, Carol Ferris, Sinestro, Atrocitus, Larfleeze, Saint Walker, and Indigo-1 (brief reference to the title of the origin arc of these characters could help newer readers)come across The Book of the Black.

On Oa, Parallax climbs into the Central Power Battery and broadcasts out to all of the Green Lanterns the message "Impurity Restored".

John Stewart, Kyle Rayner, Ganthet, Hannu, Soranik Natu, and the Alpha Lantern Boodikka are on Oa when they get affected by Parallax.

The group plans to go save Ganthet but realizes that they are underpowered, until Hal reveals that he still has the rings of Carol Ferris, Sinestro, Atrocitus, Larfleeze, Saint Walker, and Indigo-1.

They escape into the caverns under Oa and find a facility full of weapons and devices made by the Guardians, as well as the foundry, where the Corps' batteries and rings are forged.

John discovers there that Mogo is sending off hundreds of rings to space, to recruit new Green Lanterns.

With no other way to stop the planet, John absorbs the Black Lantern energy and uses it to blow up Mogo's core, killing him.

Inspired by Hal's bravery and loyalty to the Corps' ideals, Sinestro decides to help, and a Green Lantern ring chooses him, much to his shock.

Due to his 'rebellion' against them by working with the other ring-bearers, coupled with his recent murder of a Guardian, along with Scar, as well as high treason, they now believe Hal to be the most dangerous Green Lantern.

Despite Ganthet's attempt to defend him, they discharge him from the Corps, taking his ring and sending him back to Earth.