WARNING: The following contains spoilers for Doctor Strange #4, by Mark Waid, Kev Walker, Java Tartaglia, and Antonio Fabela, on sale now.
While Doctor Strange might be Marvel's Sorcerer Supreme, he wasn't Marvel's first Master of the Mystic Arts. Instead, that honor belongs to Doctor Droom. Created by Stan Lee and Jack Kirby in 1961's Amazing Adventures #1, the sorcerer who would later be known as Doctor Druid was one of Marvel's earliest recurring characters, even if he was largely overshadowed by Doctor Strange and reduced to occasional supporting roles around the Marvel Universe.
While they haven't worked together too terribly often, Doctor Strange has found himself working as a surgeon at the same hospital that Doctor Druid -- a clinical psychologist -- is working as an administrator at. And in Doctor Strange #4, these two magic users team up to save their hospital from a supernatural threat.
In this issue, Strange is asked to perform a sudden surgery on a man who's been brought in with a traumatic brain injury. However, this man turns out to be a lower demon disguised by a glamour spell. To complicate matters, this demon explodes if a scalpel touches its brain, leveling the hospital with the blast. However, Strange doesn't realize this until his scalpel is being drawn into the demon's cranium.
Powerless to stop the explosion from killing hundreds of innocents, Strange calls out to Druid telepathically, and the newly reborn sorcerer is able to draw the magic out of the demon and put it into the plants of the hospital's rooftop arboretum. While the hospital's arboretum explodes, but the hospital and everyone in it are safe.
While this is one of the first real acts of heroism Druid has committed in a while, it's hardly the first time the former Avenger has used his mystical knowledge to save the day. After discovering that he was descended from a long line of druids, Doctor Druid sought out knowledge of the occult. After years of searching, he was eventually trained by the Ancient One and was essentially considered a substitute candidate for the title of Sorcerer Supreme.
With his mystical knowledge as well as some telepathic powers, Druid served on the Avengers and briefly led that team as well as the Secret Defenders. After being worn down by the responsibilities of leadership and multiple periods of being mind-controlled, he did what any sensible person would and faked his own death to disband the team.
After faking his death, Druid spent his time getting drunk and running a sort of party house for other magic users. When one of his tenants summoned Hellstorm, Marvel's Son of Satan, Druid tried to fight him. During his match-up against the son of the Devil, the reclusive magician didn't do so well was killed and set on fire, and his remains were literally thrown in the trash in Warren Ellis and Leonardo Manco's Druid #4.
While it's not clear precisely how Druid was resurrected, his soul found its way to Weirdworld, where it gained a corporeal form. On Weirdworld, he had a castle from which he was able to use his telepathic powers to manipulate people within a certain range. But as Strange says in this issue, it's similarly unclear how his soul jumped from Weirdworld into the regular Marvel Universe.
Resurrections and unexplained returns aren't too uncommon in the Marvel Universe, but it's worth noting that Druid's return only happened after Loki brought magic back into the Marvel Universe and coincides with an influx of the kind of young magic users who make up Strange Academy. While the questions surrounding Druid's return will likely be addressed in the coming months, he was exactly where Strange needed him to be in this issue, and Druid and Strange seem set to become Marvel's mightiest mystic duo.