Warning: The following article contains spoilers for The Green Lantern #12, by Grant Morrison, Liam Sharp, Steve Oliff and Tom Orzechowski, on sale now.
Wielding a ring that can change the fabric of reality itself powered by will and shaped by imagination, the Green Lantern Corps use some of the most powerful weapons in the DC Universe to police the various galaxies.
However, as Grant Morrison and Liam Sharp's epic run on The Green Lantern closes out its first major story arc. After Hal Jordan's team-up with his multiversal counterparts, and a team of Green Lanterns, the entire DCU finds itself rewritten by the villainous Controller Mu using another, more powerful DC relic: The Miracle Machine.
Created by future Marvel Editor-in-Chief Jim Shooter and legendary Superman artist Curt Swan in 1968's Adventure Comics #367, the Miracle Machine was introduced as a device built by the Controllers, an offshoot race of the native extraterrestrials of Oa who formed their own off-world faction rather than becoming the Guardians of the Universe and helping found of the Green Lantern Corps.
Instead, the Controllers formed their own intergalactic peacekeeping force, the Blackstars, and created the Miracle Machine to make its user's deepest wish a reality, rewriting time and space as a piece of reverse-engineered Green Lantern Corps technology that likley contained elements of a New Gods' Mother Box.
The original, classic Miracle Machine was gifted to the Legion of Super-Heroes sometime in the 30th century for their assistance in defeating a renegade Controller. After Brainiac 5 used the device to stop an invasion by the Dark Circle and create a new headquarters for the Legion, the Controllers warned the team about the potential dangers such an omnipotent device could possess, leading to the Legion encasing the Miracle Machine in a block of Inertron, the densest, most resilient metal known in the 30th century, vowing only to use it when absolutely necessary.
Since then, the Miracle Machine has reappeared sporadically across various Legion of Super-Heroes stories, often used as a sort of deus ex machina to defeat seemingly unbeatable antagonists or undo catastrophic damage that had been inflicted on the universe.
The first major appearance of the Miracle Machine following the Crisis on Infinite Earths occurred during 2009's Final Crisis -- also written by Morrison -- with Brainiac 5 entrusting the designs of the Miracle Machine to Superman before sending him back to DCU's relative present, with Superman using his own energy to power the device and rewrite reality to undo the damage caused by Darkseid and defeat the God of Evil.
In The Green Lantern #12, a prototype Miracle Machine is constructed -- potentially the first in the revised history of the DC Rebirth era -- by Controller Mu using cosmic DC artifacts that appeared throughout the series. The components include a Luck Dial from Ventura, an Auran Star Band, an Anti-Matter Battery from the Anti-Matter Universe and a Green Lantern Power Ring after observing Hal Jordan's extensive use of one while on assignment on Rann. Using Hal himself as the fifth and final component, Controller Mu and the Blackstars complete their makeshift Miracle Machine to rewrite reality without the Green Lantern Corps and with Hal as a Blackstar.
As a splinter faction of the Guardians of the Universe, the Controllers have employed their own willpower-fueled cosmic peacekeeping force, the Blackstars, for decades of comic book history. Morrison and Sharp's run has focused on the Controllers and Blackstars, bringing both to the forefront of the Guardians' concerns about the fate of the DC Universe.
However, in assigning Hal Jordan to infiltrate them, they unwittingly gave their counterparts the crucial components they needed to create the first Miracle Machine seen during the DC Rebirth era, potentially leading to extensive revisions of the DCU. And with Hal now among the Blackstars' ranks, the greatest Green Lantern of them all is the universe's last hope to restoring things as they were before Controller Mu's fiendish plot.