The Upside Down is a more physical threat than ever before in Season 2 of Netflix and the Duffer Brothers’ Stranger Things. Will Byers actor Finn Wolfhard recently spilled some beans on what to expect of the Upside Down this time around. It’s still shrouded in mystery, but it’s very real.

Speaking with Toronto Sun about the Upside Down in Season 2 of Stranger Things, Wolfhard said: “I can’t say too much but we went into these tunnels. It was this giant, giant built set that you could walk through and it was really awesome.”

Rather than going for a green screen this time around, the Upside Down will supposedly consist of a collection of real tunnels set to look like the horrifying nightmare realm that Will was trapped in for most of Season 1. He escaped — with the help of his friends and family — just before he bit the dust, but something followed him out, resulting in terrible visions and flashes of his former prison.

Fans will have to wait until Season 2 premieres to find out more.

Stranger Things Season 2 premieres on Netflix on October 27.