Stranger Things season 5 will finally explain the Netflix show's biggest mystery: what the Upside Down is

Stranger Things season 5 is bringing the Netflix hit to an end – and in the process, it will answer the biggest mystery about the show.

In a new interview with Variety, co-creator Ross Duffer says he and his brother Matt knew the major questions they needed to resolve in the final season were "about what the Upside Down was."

He added: "Every season would be like, 'Should we talk about it?' And we'd go, 'No, let's wait.' And then finally, we're like, 'Well, we have to now!'"

While this is the end of the main show, there is a spin-off in the works, though, at the moment, it's pretty much a complete mystery.

In the same interview, Matt Duffer explained that neither he nor Ross wants to "increasingly expand what could become an insanely convoluted mythology" after season 5, so, according to Ross, the spin-off would "live in a bit of a different world," though "there's going to be connective tissue."

But don't get too sad about season 5 being the end, either, as it looks like the show is going out with another supersized finale. The runtimes for volume 1 have also been released: episode 1 will be one hour and eight minutes, episode 2 is 54 minutes, episode 3 is one hour and six minutes, and episode 4 is one hour and 23 minutes.

Stranger Things season 5, Volume 1, arrives this November 26, with volumes 2 and 3 following soon after on December 25 and December 31. Until then, fill out your watchlist with our guide to the best shows on Netflix.