TIME: Creator of xkcd Reveals Secret Backstory of His Epic 3,099-Panel Comic.

After more than four months of hourly updates, the journey finally came to an end last week, and the final product is 3,099 panels long–so long that the Youtube video compiling them (above) runs more than 40 minutes from start to finish. Even better, Munroe is finally talking about the elaborate backstory behind the minimalistic and seemingly ancient world of “Time,” which he reveals was set not in the past, but 11,000 years in the future.

“In my comic, our civilization is long gone. Every civilization with written records has existed for less than 5,000 years; it seems optimistic to hope that the current one will last for 10,000 more,” Munroe told WIRED. “And as astronomer Fred Hoyle has pointed out, since we’ve stripped away the easily-accessed fossil fuels, whatever civilization comes along next won’t be able to jump-start an industrial revolution the way we did.”

Which is why we need to spread civilization beyond Earth — and, really, the Solar system..