WARNING: The following contains major spoilers for Dark Ages #1, available now from Marvel.
Throughout the Marvel Multiverses, comics like What If and Marvel Zombies have introduced horrifying, tragic versions of the Marvel Universe. However, none of them has fallen as quickly as the world of Dark Ages. In less than a day, all electrical devices are rendered inert, an ancient threat is uncovered and defeated and several of Marvel's most iconic heroes are killed in Dark Ages #1, by Tom Taylor, Iban Coello, Brian Reber and VC's Joe Sabino.
Peter Parker and other heroes with Spider-Sense like his were the first to realize that something was amiss, before Moon Girl and the Watcher uncovered the source of the trouble to be the ancient, subterranean threat known as the Unmaker. This living machine, originally created to stave off entropy itself, had been imprisoned within the Earth's core after becoming corrupted by the same emptiness it had been made to consume. Now awakened after millions of years, the Unmaker's attempts to escape its confinement were tearing the world apart. Naturally, Doctor Strange led the charge to stop it with the Invisible Woman, the Thing, the Scarlet Witch and Vision, who were hand-picked for the particular skills they brought to the table. However, this mission took a horrifying turn for those Avengers.
As the Earth above is shaken to shambles by the Unmaker's incessant pounding from within, Ben Grimm leaps into action with a flying haymaker only to be met with a blast of energy that disintegrates him entirely before he can land the punch. Despite her magical hexes, the Scarlet Witch is relegated to almost the exact same fate while Vision watches on helplessly.
Before the Unmaker could eradicate the rest of its assailants, Vision phased directly into its head, which buys Doctor Strange enough time to open a portal to a dimension that contained a powerful electromagnetic pulse. This would prove to be exactly what was needed to bring the Unmaker to its end. But with its last desperate attempt to keep fighting, the Unmaker lashed out at the Sorcerer Supreme and killed Doctor Strange before he could close the portal.
After Strange died, the energy from that portal was unleashed upon the rest of the world, with the EMP knocking every electrical device on Earth. While the full devastation of this moment has only just started to play out, hi-tech heroes like Iron Man were immediately grounded, along with every plane on Earth. Anything with a current ceased to function, which seemingly led to the immediate demise of tech-based lifeforms like Viv Vision.
With only the Invisible Woman apparently walking away from the initial assault on the Unmaker, the world of Dark Ages wiped out some of Marvel's most powerful and well-liked heroes, proving that no one is safe in this alternate reality. Doctor Strange and the Scarlet Witch are two of the only characters who have the breadth of power and mystical knowledge to produce the kind of worldwide spell that would be needed to undo the effects of an event like this, which makes their loss especially pronounced. But with the devastation of the Unmaker's destruction and the resurgent threat of Apocalypse on the prowl, they almost certainly won't be the last heroes to die.