Batman is granted a Green Lantern ring.
Ganthet then congresses with him and says his presence is required in the matter of a sentient designated "Sinestro," the Green lantern who had abused his power, using it to increase his own treasure and to abuse the rights of the innocent.
Bruce then flies to another world where he meets Sinestro. A battle between the two ensues. Bruce uses Sinestro’s overconfidence to his advantage and defeats him.
Bruce captures Sinestro and brings him to the headquarters of the Green Lantern Corps on Oa. It is as spectacular as anything he had ever imagined. For the first time, Bruce begins to be aware of what he is a part of. Sinestro receives his punishment and is transported to the anti-matter universe of Qward where he is granted a Yellow ring.
Sinestro then goes to Gotham, where he causes many deaths. Bruce catches on to him, finds him, and the they fight. Bruce eventually comes out on top and Sinestro runs away. He searches for Sinestro for days, but he was unable to find him. During his search, Cat, Star Sapphire and Harvey Dent ambush him. He overcomes them and they run away.
Bruce continues his search but is still unable to locate them, for Sinestro’s yellow cloaking field cannot be penetrated by his power-ringed satellites.
By defying an order mad by Ganthet, Bruce was ordered to surrender the ring immediately. Four Lanterns, Katma Tui, Tomar Re, Kilowog, and Arisia are sent to retrieve the ring. While they are occupied fighting, Sinestro breaks into Bruce’s hideout and tampers with his Lantern so that the next time he charges his ring it would kill him. He was unable to complete the job when Green Lantern’s Superman, Flash, and Wonder Woman step in to stop him. Sadly though, Alfred died in the midst of battle.
Bruce then leaves the world behind, his possessions, his legacy, and his home. He vows to find Sinestro and get revenge.