A Guardian of the Universe comes to Earth to recruit Batman to help him learn which Guardian is an impostor, and to restore Hal Jordan's memories of being Green Lantern. Batman, who is busy on a mission, asks the Guardian to help him first and with the Guardian's help, Batman manages to solve a case in record time.

Once free from his duties, Batman and the Guardian go to Ferris Aircraft, where they find Hal, but realize that he has lost his memory about the Guardians and his Green Lantern identity. The Guardian and Batman work together to bring back Hal's memory and when he finally remembers his identity, Hal also remembers that Sinestro is somehow responsible for his amnesia. The Guardian then realizes that Sinestro might also be involved with the impostor Guardian and several other troubles the Green Lantern Corps have recently had. It is then that Batman suggests going to Maltus, the Guardians' home-world and Green Lantern asks Batman to join them on their quest to stop Sinestro.

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