WARNING: The following contains spoilers for The Green Lantern #3 by Grant Morrison and Liam Sharp, on sale now.
At the core of Green Lantern is the idea that mankind -- and all sentient life -- can form order out of the chaos that is the universe. That there can be laws and regulation, even a fundamental concept of right and wrong, despite all the terrible things that happen to innocent people. The problem, of course, comes when you realize that the members of the Green Lantern Corps are still just as fallible as those they try to put away.
The Green Lanterns have always been depicted as a peacekeeping force, but in Grant Morrison and Liam Sharp's The Green Lantern, they are now space cops. There is protocol to follow and decorum to keep in mind, but everything goes wrong in Issue #3, when Hal Jordan straight up murders a criminal.
A Man Can Only Take So Much
Sometimes even the most experienced and skilled veterans see more than they can handle. After witnessing horrific acts across the universe, and even withstanding his own time as a maniacal space tyrant, it's hard to believe that anything could ever be too much for Hal Jordan. Still, it would seem that even one of the most decorated Green Lanterns of all time has his breaking point.
Earth has been shrunk and stolen to be sold at a black market auction to the worst villains in the cosmos. Despite the response from the Green Lantern Corps, the planet is still awarded to the godlike being known as the Shepard. Though Jordan attempts to save his home planet, this entity is able to influence the people of Earth into being comfortable with their fate.
Witnessing humanity's willingness to become food for a cosmic carnivore proves to be too much for Hal to bear. He forcefully takes the planet under his protection and returns to salve trader Vulgar Zo all sorts of pissed off. Unfortunately, there are far more disturbing activities still to be discovered by this very angry and very human police officer to the stars.
Apparently, the fuel used to power the slaver's ship is also incredibly toxic to those held captive on it. Hal returns to find that children have been poisoned with lethal doses of toxic radiation. These slaves have been mutated and are destined to die despite the Green Lanterns arriving to save them.