All the moments in the first volume of Stranger Things 4 seemed to have culminated in Dear Billy, when Max Mayfield (played by Sadie Sink) was ensnared in the Upside Down. This was the very scene that catapulted Kate Bush’s Running Up That Hill to the pinnacle of Billboard’s Hot Rock & Alternative Songs Chart, 36 years after the song was first released.
In a new video that takes you behind the scenes of the now-famous sequence, Netflix reveals that much of the Mind Lair comes from practical effects.
Vecna, for one, was fully-suited in his ghastly costume, and the staircase and blood-drenched floor were indeed real.