End of the World

The End of the World was a vision of the future foreseen by Dinah Alcott and prepared for by multiple parties, including Cauldron, The Protectorate and Slaughterhouse Nine.

Discovery
During the attack of Slaughterhouse Nine on Brockton Bay Coil asks Dinah Alcott for the likelihood of any of his groups encountering the members of the Slaughterhouse. When Dinah sees the image of Jack Slash on the computer screen, she informs Coil and gathered Undersiders that Jack is the catalyst for the event that kills most of the humanity:

"“It’s him.”

“Who?”

She pointed at the screen, at Jack Slash. “Him.”

“You’re going to have to explain it to us, pet. What about him?”

“He’s the one who makes everyone die.”

I shivered. What?

“Everyone here?”

Dinah shook her head, her hair flying out to either side. “Everyone. I don’t understand. Can’t explain.”

“Try,” he urged her.

“Sometimes it’s in two years. Sometimes it’s in eight. Sometimes in between. But if he’s alive, something happens, and everyone on Earth starts to die. Not that everyone doesn’t die anyways but they die really fast when that something happens, all one after another, and in a year almost everyone is dead. So I said everyone, if that makes sense and a few live but they die pretty soon after anyways [...]“"

Further down she clarifies that even if Jack is killed the event still happens, but the timeline changes:

"“I think we need more numbers if we’re to understand this, pet. What is the likelihood that he succeeds in this? To one decimal point.”

“Eighty three point four percent.”

“You said if he’s alive. What if we killed him? Now? To one decimal point. If I use my power.”

“Thirty one point two percent chance someone kills him before he leaves the city, if you use your power. It doesn’t happen until fifteen years from now, if you do.”

“So it still happens?” Coil asked.

“Yes. Always happens.”

Tattletale spoke up, “He’s the catalyst for something else, then.”

“Is it always successful, pet? This something that kills everyone on Earth?”

She shook her head, “Not always, not all the way. Sometimes more people live. Sometimes hundreds, sometimes thousands, sometimes billions. But millions or billions always die when it happens.”"

Reactions
Coil informs the heroes of the prophecy during the meeting and discussion of Slaughterhouse Nine presence in Brockton Bay:

"“I’m inclined to agree,” Coil answered, after a moment’s consideration. “Perhaps now is an opportune time to share this information: I have sources that inform me that should Jack Slash survive his visit to Brockton Bay, it bodes ill for everyone.”

“That’s vague,” Faultline spoke.

“I’ll be more specific. Should Jack Slash not die before he leaves Brockton Bay, it is very likely the world will end in a matter of years,” Coil spoke.

“Bullshit,” Skidmark answered. The others were showing varying reactions. I doubt many bought it.

“You contacted us to say something very similar a couple of days ago.” Miss Militia said, “But I have the same questions now that I did then. Do you have sources? Can you verify this? Or provide more information?”

Behind her, Weld reached into his pocket and withdrew his smartphone.

“More information? Yes. I have sought further details and pieced together a general picture of things. Jack Slash is the catalyst for this event, not the cause. At some point in the coming years, Jack Slash kills, talks to, meets or influences someone. This causes a chain of events to occur, leading to the deaths of anywhere from thirty-three to ninety-six percent of the world’s population.”

That gave everyone pause.

Coil went on, “If Jack Slash is killed, the event is likely to occur at some point in the more distant future instead.”"

After Jack successfully escapes Brockton Bay the heroes Dragon and Defiant set out to destroy the Slaughterhouse Nine.

Endgame
Weaver leads the attack on The Slaughterhouse Nine-Thousand, which deliberately excluded heroes like The Triumvirate who might be powerful enough that they could trigger the end of the world single-handedly.

Saint, theorizing that her increasing freedom to follow the Nine was what led to the end of the world, neutralized Dragon with the Deployment of Ascalon.

Jack Slash threatened to order his army to kill as many people as possible, which he suggested might be the prophesied end of the world, if the heroes broke the rules of his game with Theo Anders.

Weaver killed Aster because she worried the child might be about to trigger with a power that would cause the end of the world.

Nature
The avatar of the Warrior Entity was the one to destroy the world (See Scion), a fact known prior to the prophecy by Cauldron, organization created explicitly for the purpose of improving humanity's chances in face of this event.

The End of The World happens approximately two years after Dinah's predicition and is commonly referred to as Gold Morning.