In Mogo, Texas in the 1600s there is a bank robbery taking place. Two crooks enter the building guns blazing and take the money. They then run away thinking that they have won when all of a sudden, a green wall appears in front of them. They both crash into the wall and fall down. Above them stands Hal Jordan, the sheriff of Mogo and a member of the Green Ringed Officers. "Y'all thought you could get away" says Hal. "The Green Ringed Officers are not going to let no chaos happen in our town. Y'all should have known that." Hal then creates a jail cell around the criminals using his ring, and gets on his horse and rides away, dragging the jail cell with him. On his way to jail, Hal is attacked by a sonic scream. Hal flies off of his horse, knocking him out. The person revealed to have done this was the supervillain, Sonar. "You idiots" says Sonar to the captured crooks. "You guys can't be trusted to do anything yourself. Now come along, the boss is waiting for you." Sonar and the crooks leave.
A few hours later, Hal wakes up in Ion, the HQ of the Green Ringed Officers. When he wakes up, he is greeted by Collin "Kilowog" Haynes, or just Kilowog as he is so often called by his friends. Kilowog is also a Green Ringed Officer. "What happened out there?" Kilowog asks. "You let the criminals get away." "I was caught off guard by that attack from Sonar okay" says Hal trying to create an excuse. "Well you 'ought to get your mind straight" says Kilowog. "Because we have work to do." Hal and Kilowog walk into a room, and they are briefed on a mission by Kramoris or "Krona" the commander of the Green Ringer Officers. They are told that Sonar, the two crooks, and the criminal genius, Hector Hammond have all been hired by former Green Ringed Officer member, Sinesio Korugar, or how he's known on the streets, Sinestro. "I think Sinestro is tryin' to form some kinda gang to go up against the Green Ringed Officers" says Krona. "Your mission is to put a stop to Sinestro's plans and bring him and his gang to justice!"
While Hal and Kilowog are being briefed, Sinestro, Hector Hammond, Sonar, and the two crooks, Arkillo and Ampa Nnn are going to a gun shop. When they enter the gun shop, the cashier lets them go behind the desk and into the room entitled, Employees Only. When they enter room, they find a man named Parry o Laxmaiah, or his criminal name, Parallax, manufacturing a couple of yellow rings. "Are they ready" Sinestro asks. "As ready as they'll eve' be" says Parallax handing the members of Sinestro's gang the rings. "I based off of the design of the Green Ringed Offic'as, but with a new power source" says Parallax as Sinestro's gang puts on the rings. Parallax then holds out his hand to Sinestro, obviously asking for his money, but Sinestro blast Parallax into a table. "You can't trust nobody in the wild west" says Sinestro to Parallax. "You of all people should know that." Sinestro and his gang then walk out of the gun shop and back to their hideout.
Later, Hal and Kilowog are trying to get a lead on Sinestro's whereabouts, interrogating various criminals, but getting no answer. Then, Hal hears someone call someone call his name. The sound came from a gun shop so Hal and Kilowog walk inside. They are then led by the cashier to the Employees Only room where Parallax is sitting at his desk. When Parallax gets up from his desk, Kilowog notices a huge mark on his stomach. Hal asks what happened, so Parallax explains everything. He then goes on to tell Hal and Kilowog where Sinestro could be which is the basement of the restaurant, Thaal's Bar. Hal and Kilowog thank Parallax and the two venture over to Thaal's Bar.
When they get there, they attempt to go to the basement, but they are stopped by a bartender, who pulls out a rifle. Then the bartender starts shooting at Hal and Kilowog. Kilowog creates a shield while Hal creates two revolvers and makes them shoot at the bartender. Seeing that he is outmatched, the bartender takes cover. He then reloads his rifle and just as he is about to shoot Kilowog and Hal, Kilowog creates a cannon and shoots the bartender, knocking him out. Hal and Kilowog then walk to the basement and they start attacking Sinestro and his gang. Unfortunately, they are overwhelmed and their Green Rings run out of power. With no more power, Hal and Kilowog are easily defeated, but before Hal is knocked out, he utters 'I'm sorry family, I have failed you.'
A few hours later, Krona hears about the defeat of Hal and Kilowog, so he contacts a different group of officers to get the job done. Krona uses a ring to contact them. Meanwhile, a group of five officers is in the middle of a mission in the woods when one of them receives a call from Krona. He replies while running and he and his group are briefed on their next mission as they are running through the woods. Then the man hangs up and the story transitions to Krona saying "I can always trust them to get the job done when all else fails. They're the executioners, the Manhunters." The story then transitions back to the 5 officers, or the Manhunters, running through the woods. When they get to their destination, the hideout of a Native American tribe, they immediately start attacking, creating guns and shooting everyone in sight. One Native American father, Atrocitus, tells his wife and child to run away, but before they can, they are both killed. Atrocitus screams in sadness and when the chaos is over, Atrocitus and his pet snake, Dex'tar are the only survivors. Atrocitus is furious at this point and suddenly, a red aura surrounds him.
Back at Thaal's Bar, Sinestro uses his yellow ring to hold Hal and Kilowog upside down. "Wake up, Hal." Hal Jordan slowly opens his eyes. "Sinestro." "Hello Jordan." "You crooks won't get away with this. I will bring you to justice." Suddenly the basement door flies open and out steps the Manhunters. Sonar notices them first. "Sinestro, watch out-" Sonar is impaled by a sword construct, killing him. Soon after, one of the manhunters jumps down the stairs and creates a rifle construct. He then shoots Ampa Nnn in the chest, sending him flying backward into the wall. Arkillo creates a machine gun construct in retaliation, but is soon shot at by the Manhunters. "Stop it!" Hal yells. "Your killing them." Hector Hammond uses his powers to attack the minds of the Manhunters, but after some brief pain, the Manhunters create an anvil and crush him with it. Realizing that he is the only one left, Sinestro blasts all of the Manhunters in the chest, hurting them, but not fatally. As a result, the Manhunters get back up, create gun constructs and attempt to shoot Sinestro. Sinestro, creates a shield, deflecting all of the blast. The Manhunters realize that their guns will not get past Sinestro's shield, so they combine their powers to create a train. They then use the train to ram over Sinestro. This plan proves Sinestro as Sinestro is killed by the attack. "Noooo!" Hal yells. Because Sinestro is dead, the construct holding Kilowog and Hal upside down, fades away, sending the two falling to the ground. One Manhunter attempts to help Hal up, but Hal refuses to accept his help.
"You call yourselves heroes" Hal says mockingly. "When you too are murders!" Hal takes off his ring. "I can't serve in an agency where the members are heartless murders. Ha; throws down his ring and walks away, leaving behind the Manhunters and Kilowog.
A few days later, a slave is being forced to work on the fields. Then out of the blue, a green light appears and two men in uniform approach the slave. "John Stewart. You have been chosen to be able to join the Green Ringed Officers. Welcome to the agency." John Stewart is then given a green ring and the three teleport away.