Writer: Robbie Thompson; Artist: Javier Rodriguez; Inker: Alvaro Lopez; Letterers: VC's Joe Caramagna; Colorist: Jordie Bellaire; Editor: Nick Lowe; Editor-in-Chief: Axel Alonso; Cover Artist: Raphael Albuquerque (# 1), Javier Rodriguez (# 2-3)
In a mystical cave in England, in the year 590 AD, the sorcerer Merlin is about to lock away a creature he has created. He is confronted by King Arthur and another wizard named Bohra, who Merlin reveals to be another of the creatures. Merlin claims that the creatures are evil and locks them away behind a door before leaving with Arthur.
In the present day, a vastly depowered Dr. Strange is fighting a tentacle demon named Q'uvin the Malevolent in an alley beside his Sanctum Sanctorum. Merlin arrives to help fight the beast, who Strange is able to kill with his axe. Merlin takes Strange through a time travelling dimension, saying he needs Strange's help against an evil creature called the Forgotten who is collecting magical relics. They arrive in the past and locate the other Sorcerer Supremes that Merlin has enlisted: Wiccan, Kushala, the Conjuror, Sir Issac Newton and his Mindful One, and a young boy that Strange recognizes as the eventual Ancient One. After a brief battle against the Forgotten's minions, Strange talks to Wiccan, who is the Sorcerer Supreme from the future, and asks what's going on. Merlin gives a key to the Conjuror, then the two of them speak with Kushala the Demon Rider, who tells them that when she touches the earth she senses great power. The Forgotten bursts from the ground and attacks, grabbing Merlin and swearing revenge on what he has done to "them". He then crushes Merlin in his hand and tosses him to the ground, while simultaneously knocking around the other sorcerers with ease. Strange makes his way to the fallen Merlin, who requests that Strange finish his mission then dies in his arms.
In the near future, Sorcerer Supreme Wiccan holds off a demonic invasion, and is whispered a secret before the demon queen dies. At the battle with the Forgotten, Merlin has been killed and the other Sorcerer Supremes are unable to defeat the giant. Yao, the future Ancient One, has his arm broken, which prompts Wiccan to scoop up his allies and teleport them away from the battle. They arrive on a beach, where they sink into one of Merlin's traps that is meant to capture their souls. Sir Issac Newton's servant, the Mindful One, rescues them due to it not having a soul. The Sorcerers travel through the forest on their way to Merlin's home, but find Camelot in serious disrepair. The Forgotten, meanwhile, is on the way to Camelot as well to find the Sorcerers. Back in the future, Merlin approaches Wiccan and ask what he had been told, and Wiccan tells him that he is dying. Merlin offers to remove the curse that is killing him if he travels with him to fight the Forgotten.
In the 1800s, a Native American woman named Kushala witnessed the massacre of her people by United States cavalrymen. In her anguish she is possessed by the Spirit of Vengeance, which incinerates all of the soldiers. Ever since she had traveled the world, learning magic while being followed by the ghosts of her victims, to try and find a way to rid herself of the "Demon Rider".
In the time of Camelot, Kushala and the rest of the Sorcerers Supreme have broken into Merlin's castle and finds all of the people inside alive but catatonic, their souls having left their bodies. The sorcerers move deeper into the castle and locate Merlin's library, which they hope will include a way to stop the Forgotten. In the library, Kushala finds a box but damns Merlin when she sees that the box's contents are gone. They find a list of names written by Merlin of sorcerers that he captured and locked away because they were practitioners of "darker magic". The group is then attacked by the spirits of the castle dwellers, who Kushala remarks have "turned". Outside, the Forgotten senses that Merlin's protective wards have been broken, and he ventures inside. The Forgotten arrives in the library and destroys some of the spirits, which angers Kushala due to them being innocent victims. She transforms into the Demon Rider and attacks the Forgotten, who eventually flees after claiming a mysterious book from the library. Later, after returning the spirits of their bodies, the sorcerers realize that the Forgotten isn't just one being, it's all of the magicians Merlin locked away combined into one entity. Isaac Newton tells them that the Forgotten must be destroyed and directs them to where the Forgotten said it was going, the Hollow Out of Time.
Finally, in a flashback, Merlin promises Kushala that if she helps him then he will remove the Spirit of Vengeance from her permanently.
In the time of Camelot, Kushala and the rest of the Sorcerers Supreme have broken into Merlin's castle and finds all of the people inside alive but catatonic, their souls having left their bodies. The sorcerers move deeper into the castle and locate Merlin's library, which they hope will include a way to stop the Forgotten. In the library, Kushala finds a box but damns Merlin when she sees that the box's contents are gone. They find a list of names written by Merlin of sorcerers that he captured and locked away because they were practitioners of "darker magic". The group is then attacked by the spirits of the castle dwellers, who Kushala remarks have "turned". Outside, the Forgotten senses that Merlin's protective wards have been broken, and he ventures inside. The Forgotten arrives in the library and destroys some of the spirits, which angers Kushala due to them being innocent victims. She transforms into the Demon Rider and attacks the Forgotten, who eventually flees after claiming a mysterious book from the library. Later, after returning the spirits of their bodies, the sorcerers realize that the Forgotten isn't just one being, it's all of the magicians Merlin locked away combined into one entity. Isaac Newton tells them that the Forgotten must be destroyed and directs them to where the Forgotten said it was going, the Hollow Out of Time.
Finally, in a flashback, Merlin promises Kushala that if she helps him then he will remove the Spirit of Vengeance from her permanently.