'Stranger Things' is now filming Season 4

Something is brewing in the Upside Down — the fourth season of "Stranger Things!"

On the hit series' Facebook page, it was announced that filming is now underway.

The cast had reunited for a table read back in March, and yes, they were all there, including David Harbour, confirming that Hopper will be making a comeback.

Netflix has yet to announce the premiere date for the highly-anticipated fourth season. Season 3 was released in July last year.

"Stranger Things," created by the Duffer brothers, follows a gang of misfits, including superpowered Eleven (Millie Bobby Brown), as they try to fend off monsters from the alternate dimension called the Upside Down. 

The series premiered on Netflix in 2016. —JCB, GMA News