The latest episode of The Flash teased that the Fastest Man Alive will soon find himself faced with the Red Death, an evil, super-speedster version of Batman. Barry Allen has always lived his life in the shadow of a dark future, one in which he mysteriously went missing in an event that seems tied to the "Crisis on Infinite Earths." But the latest episode saw Barry and Iris actually experience this future timeline - after a fashion.
Team Flash decided the best way to deal with Cicada was to appeal to his heart by getting his daughter Grace to awaken from a coma. Sherloque knew just how to pull it off, revealing a memory machine that would allow them to enter into Grace's mind and encourage her to awaken. Naturally, things didn't work out as planned; XS went in ahead of the others, and wound up stranded. When the Flash and Iris transported themselves after her, they accidentally got caught up in Nora's (future) childhood memories. Barry even got to do a tour of the Flash Museum - filled with merchandise that exists in the real world.
Related: How The Arrowverse Has Already Set Up Crisis On Infinite Earths
In one key scene, the young Nora listened to an automated recording talking about one of the Flash's greatest enemies, Cicada. It was a chilling speech, revealing that Cicada was never defeated, in spite of the best efforts of the Flash and his friends. But it also name-dropped another key villain. "Cicada killed more people than Zoom," the recording explained, "or even the Red Death." That's a reference that will make any DC comic book reader sit up and take note.
The Red Death is a relatively new character in DC comics lore, created by writer Scott Snyder and artist Greg Capullo as part of the "Dark Nights: Metal" event. He's a twisted version of Batman from another reality, who was broken by the deaths of several of his Robin sidekicks. Believing he needed something more, Batman decided he had to acquire the Speed Force. His plan was simple; use the Speed Force to rewrite history, averting all the tragedies he has seen in his long life, all the way back to the deaths of his parents. Flash knew better, having tried to do the same once, and he refused to help.
That particular Earth was ultimately consumed by a hidden Dark Universe, falling under the thrall of a monstrous being named Barbatos. As the Earth crumbled, Batman decided there was only one way to save everyone. He used the Rogues' old weapons to beat the Flash, and attempted to steal the Speed Force from him. Instead, he wound up bonded to the Flash - but his was the mind in control, and he could wield the Speed Force with ease. Tragically, even with the help of the Speed Force, Batman was unable to save his world; but he was just broken enough to be seduced by Barbatos, becoming one of his servants and taking the name "Red Death." When the Red Death finally arrived in the normal DC universe, he proved to be a terrifying foe, whose very presence sapped the Speed Force from anyone around him.
When it comes to The Flash, it's best to take references like this seriously. Back in season 3, the episode "Abra Kadabra" saw a time-traveling magician reel off a list of the Flash's greatest foes, name-dropping DeVoe. The Thinker became the main villain of the very next season, and it's reasonable to assume this is intended to be foreshadowing as well. If that's the case, it's interesting to note that the Arrowverse is growing increasingly in characters tied to Batman; this year's "Elseworlds" crossover took the assembled heroes to Gotham City, and The CW has signed off on a pilot for the Batwoman TV series. It looks as though the shadow of the Bat is about to fall over the Arrowverse - but in a very dark way indeed.
More: Everything We Know About Batman In The Arrowverse
The Flash season 5 continues with episode 13, "Goldfaced", on Tuesday, February 5th at 8 PM on the CW.