WARNING: The following contains spoilers for The Flash #762 by Joshua Williamson, Howard Porter, Steve Wands, and Hi-Fi Designs, on sale now.
As Joshua Williamson's run on The Flash comes to an end, a legacy villain was re-introduced and teased to become a thorn in Barry Allen's side. And now, it seems as if Doctor Alchemy is plotting something that will almost certainly require the attention of Central City's favorite speedster.
In The Flash #762, Barry and Reverse-Flash enter into their endgame as they once again find themselves in a deadly fight. However, Barry decides to do something different in this fight and forgives Thawne for everything he's done, including killing his mother. This ploy catches Thawne off guard, and Barry takes advantage of this and vibrates at the right frequency to infect Thawne with a bit of his own Speed Force energy. This grounds Thawne back in reality and erases Thawne's life as the Reverse-Flash as well as his memory of ever having been the Reverse-Flash.
As Barry celebrates Thawne's final defeat with a big cookout with the extended Flash Family, he ponders that "there's always danger in the Multiverse, or right here in Central City." As he speaks these words, a lone figure dressed in a green-hooded robe surrounded by candles while reading from an ancient-looking text is seen. The only word the mysterious figure speaks is, "Soon." Fans of The Flash will recognize this figure as one of Barry's recurring villains, Doctor Alchemy.
There are three Flash villains who have used the name Doctor Alchemy. The first, Albert Desmond, was introduced in 1958's Showcase #13, by John Broome and Carmine Infantino, as Mr. Element, and appeared in Showcase #14 as Doctor Alchemy. Desmond is a chemist with a split personality who used his expert knowledge of science to make weapons. After being sent to jail, he discovers the existence of the Philosopher's Stone, steals it, and uses it to transform the molecular structure of anything in the world.
The second version of Doctor Alchemy is Curtis Engstrom, introduced in 1992's The Flash #71 by Mark Waid and Greg LaRocque. Engstrom is an adviser at S.T.A.R. Labs when the facility acquired the Philosopher's Stone. The scientists there intended to use a fragment of the Stone in a computer. Engstrom donned his own Doc Alchemy costume to steal the Stone and after being defeated, was sent to prison.
Created by Geoff Johns and Alberto Dose, the most recent version of Doctor Alchemy is Alexander Petrov, who debuted in 2003;s The Flash #202. Petrov was a criminologist who developed a taste for murder after using one of the original Doctor Alchemy's weapons to kill a co-worker in order to get a job promotion.
Since Barry Allen has gone up against three different versions of Doctor Alchemy, it'll be interesting to see which version, if any, will appear in future issues of The Flash. Judging from the image in The Flash #762, it looks as though the original Doctor Alchemy Albert Desmond is back. But no matter which one it is, it seems like Barry Allen's salad days won't last for long.