WARNING: The following contains spoilers for The Flash Season 8, Episode 2, "Armageddon, Part 2," which aired Tuesday, November 23rd on The CW.
The Flash Season 8 began with Barry Allen confronted by the extraterrestrial antagonist Despero who arrived from ten years in the Arrowverse's relative future and intent to kill the Flash. Pressed for more information, Despero reveals that Barry will descend into insanity and destroy the world in his madness, with Despero determined to stop this from coming to pass. And while an impromptu team-up with former Legend of Tomorrow Ray Palmer led Despero to agree giving Barry one week to prove his innocence and avoid being executed where he stood, the latest part of the "Armageddon" crossover event suggests that Despero may have been right about Barry all along.
Despero informs Barry that his breaking bad will comes from pressures on his mind causing his sanity to snap, hinting that a cataclysmic event will happen to him the following day and that, should he show any signs of his prophesied insanity, he will intervene and kill Barry on the spot. Team Flash speculates that Barry's recent speed boost from the end of The Flash Season 7 fuels this mental decline while Killer Frost suggests Chester build a weapon to deal with Despero, a request that visibly unnerves Chester as he has never used his intellect towards creating weaponry before and is a committed pacifist ever since a childhood incident that had him accidentally burn down his best friend's house.
Arriving at a crime scene of a man who violently descended into madness, Barry learns he is under federal investigation under suspicion that he assisted the villainous Joe Carver in spying on the Central City Police Department two years prior. While Kramer is sympathetic to Barry, she informs him that the investigation is beyond her control and has Barry turn in his badge until his name is cleared. Before Barry can continue the investigation on his own, suspecting it is linked to his own mental condition, S.T.A.R. Labs is shut down by the authorities when a radiation leak is detected, with the authorities planning to demolish the entire facility once the radiation has been contained and removed. In order to preserve his secret identity, Barry wipes the lab's memory banks as he and his friends gather their things and leave.
Team Flash discovers a psychic supervillain named Xotar is on the loose and the likely culprit behind turning Barry insane. Tracking down Xotar, Barry races to stop her lasting plot only to find himself back in the loft where he nearly attacks Chester before the rest of the Team Flash temporarily puts him down until he regains his senses. Meeting with Despero privately, Barry learns that the alien tragically lost his entire home planet Kalanor to a similar incident as what will happen to the Flash and seeks to avert the same grim fate from befalling Earth as Kalanor all because he didn't act in time. Meanwhile, Team Flash works with Alex Danvers to learn more about Kalanor and the source of his powers, the Flame of Py'tar.
Confronting Xotar when she attempts to stage an art heist on an armored car, Barry gets knocked around by the villain's telekinesis before he allows himself to build up his lightning before using it to lash out and incapacitate Xotar, instantly clearing those affected by her powers. As Team Flash celebrates in the aftermath, Barry is shocked to discover that Joe West died six months prior but he has no memory of this tragedy. As Barry attempts to learn what happened, a news report reveals that the Flash has seemingly snapped, with footage showcasing Barry using his speed lightning to deliberately injury dozens and cause millions in property damage as the authorities launch a citywide search for him.
Following the news report, Despero arrives in the West home to finish off the Flash, with Cecile's empathic powers proving no match for the alien. Breaking his vow for the greater good, Chester unveils a weapon that gives Barry enough time to flee to safety; a frustrated Despero warns the rest of Team Flash to stay out of his way for face the consequences as he reverts into his true, monstrous form. While Alex informs Team Flash she has found some leads on Kalanor and Despero, Barry retreats to the Hall of Justice, where he finds Black Lightning waiting for him, as the two heroes prepare to team-up and get to the bottom of what's been plaguing the Flash.
To see Barry go up against Despero, The Flash Season 8 airs Tuesdays at 8pm ET/PT on The CW.