Part 3 of "Secret Origin" explores the beginnings of Earth's Green Lantern — Hal Jordan! Hal meets the Green Lantern who will teach him everything he knows: Sinestro! But Sinestro has another mission on this primitive mudball called planet Earth…a mission not even the Guardians of the Universe are aware of.
• Hal is amazed at what he was able to do with the power ring from the last issue but at the moment the only thing he's really paying any attention to is Carol Ferris. We see that Tom is amazed right away at what Hal as Green Lantern can do, but not everyone is as impressed. Hector Hammond seems jealous at first by the appearance of the new superhero but then is interested in the fact that Hal seems new to his powers and offers Hal the opportunity to assist him in helping him understand what he is capable of. Hal turns down the offer. Carol seems very impressed with Green Lantern and tells of Hector Hammond, saying that he's a employee and she doesn't date employees. Hector reminds Carol that he is a consultant to Ferris Aircraft and that she can't speak to him that way but a phone call takes him away from the confrontation.
• Hal goes back to the crash site and tries to figure out who the mysterious alien was. He surmises that he must have been some kind of solider or officer and makes a burial for the fallen Abin Sur feeling that it was the right thing to do Hal then picks up the green lantern in the ship. The ring explains to Hal that the lantern is his power battery and suddenly, the ring becomes locked onto the battery which freaks out Hal just a bit. Then the ring tell Hal that his training is about to begin and Hal is transported to OA.
• Hal arrives at OA and things don't start off so smoothly for Hal. He is almost run over by another Green Lantern flying in his direction who has less than nice words for the newcomer. As Hal tries to figure out where he is, a fin-headed alien looks at Hal and senses something is wrong with his friend Abin Sur as he can tell the Earth man has Abin's ring. The ring then brings Hal to a group of rookie and plops him in the mud. Someone tells Jordan that he needs to treat his battery better and ribs him a bit on his landing. Welcome to ringslinging 101. Meet your instructor, Kilowog. Hal and Kilowog don't start things off on the right foot when Kilowog pushes Hal back in line with the rest of the rookies, Hal fights back and makes a giant green boxing glove and take Kilowog out with one punch. When Ch'ip tell Hal he shouldn't have done that and Hal asks why, Kilowog says because he's been waiting all day to find someone to make an example out of.
• The army is investigating two crashed landings that they had been monitoring. Major Stone is leading one of the search parties and Hector Hammond is along to help identify what they find. What they find is a crashed space ship. However when ground troops go in to investigate, the newly freed Atrocitus appears from underwater, killing the soliders and claiming that death will come to all that the Green Lantern Corps rule over. He swears by the survivors of sector 666.
• Back on OA, Kilowog is showing the rookies about how to make a force bubble by "volunteering" Hal to be inside the bubble. Ke'Haan is giving praise to a rookie named Ahtier, but wonders why he is so quiet. The rookie responds by saying that he fears his duty and that Green Lanterns are supposed to shine bright but in the end, their lights burn out quicklyand Ke'Haan responds by saying that if the human can make it, so can he. Hal wills himself out of Kilowog's bubble which seems to impress Kilowog a bit but then Kilowog throws a yellow disc at Hal and it goes right through Hal's emerald hand and smashes him in the face. The other rookies wonder why Hal tried to use his ring against the disc as everyone knows that the ring does not work against anything yellow. When Hal questions why the ring wouldn't work against anything yellow, Kilowog and him have some words before being interrupted by Tomar Re.
• Tomar Re introduces himself to Hal and tells him that he is the Green Lantern of sector 2815 which more or less makes them neighbors. Tomar asks Hal how Abin died and he tells Tomar that Abin died when his ship crashed in the desert, which puzzles Tomar as he explains that Abin didn't need a ship. Hal asks Tomar why then Abin Sur would use one and he explains to Hal that Abin Sur allowed himself to feel fear. He also goes on by telling Hal that Abin Sur disobeyed the Guardians territorial edict by pursuing an enemy outside of his sector. Abin Sur was after a group called the Empire of Tears. After his encounter, Abin Sur became paranoid. He became obsessed with Doomsday Prohechies and Prisms. Fractured light and splintered souls. Nothing Abin said seemed to make sense which Hal replies that nothing makes sense to him now. Tomar Re shows Hal the great book of OA and how the tales of the Green Lanterns are recorded there and that one day so will his. Tomar then tells Hal that if you ever need help, ask for it.
• Hal continues on with his training alongside the other rookies as Kilowog and Ke'Haan take them through the steps of becoming a full-fledged Green Lantern. They continued to practice until the day came that Ke'Haan and Kilowog felt that their training was over. All of them had done well and Hal and the rest of the rookies earned their Green Lantern badge. All of the rookies powered their rings with the main power battery as they recited the Green Lantern oath and as Hal did it, his Green Lantern badge appeared on his chest. He had become a full-fledged Green Lantern.
• Elswhere, a Green Lantern is asking one of the Guardians why he was not told of Abin Sur's fate and the Guardian replied that the Green Lantern was busy and they did not want to distract him from his duties. When the Green Lantern said when has his he ever been distracted, the Guardian commented that his record was far superior to other Green Lanterns and that he was considered the greatest by many. The Guardian tells the Green Lantern that his new assignment is to go to Earth and contact Abin Sur's replacement and investigate the circumstance of his death. He also tells the Green Lantern to call him Ganthet. The Green Lantern is surprised as he thought the Guardians didn't have names. Ganthet tells the Green Lantern that it is so that he will know him. The Green Lantern says that it's against the terriotorial edict for Green Lanterns to team up but Ganthet tells him to break that edict for his mentor and friend. The Green Lantern agrees and Sinestro is on his way to Earth. See ya next month when Hal Jordan meets Sinestro for the first time.