If you were wondering how Kate Bush granted permission to the Netflix show, then ponder that thought no longer.

Thanks to Sadie Sink and her character Max, the '80s pop star has been enjoying a resurgence in the music scene - but it also turns out that Kate Bush is a huge 'Stranger Things' fan, which is how her music ended up being used as a pivotal part of the show.

If you haven't already seen the first four episodes of season four, then here's your official *SPOILER* warning.

The big bad of the season, Vecna, is busy preying on innocent teens in Hawkins, making them relive psychologically damaging moments from their past, essentially making their depression or anxiety 100 times worse. With a line of bodies lying in his wake, Max, who is dealing with the loss of her older brother and her mother's addiction, becomes the villain's latest victim.

Luckily for her though, in episode four titled 'Dead Billy', she's got an '80s icon (and some intelligent friends) on her side to save the day. Sidenote - give Sink that Emmy nomination.

As reported earlier this week, since the fourth season of the sci-fi/fantasy series premiered on Netflix last Friday, her track 'Running Up That Hill (A Deal With God)' has been tearing up music charts all over the world. But how did a Kate Bush song end up on the series? It's because she's a big 'Stranger Things' fan.

Per Variety, the show’s music supervisor, Nora Felder, was tasked with finding the perfect song choice to save Max's life AND then to reach out and hope Bush and her team would approve the track to be used. You see, the star doesn't typically hand out many music approvals.

Felder told the publication how the hit song "immediately struck me with its deep chords of the possible connection to Max’s emotional struggles". Once showrunners The Duffer Brothers loved the suggestion, she and the clearance coordinator then had to "create elaborate scene descriptions that provided as much context as possible" to showcase how well the song integrates into the storyline.

While the deal took longer than normal to iron out, because of how often the song is used, in the end it was in the bag as "Bush was also a big fan of the show". Variety writes: "Once the team could understand the intent and vision, Bush granted her permission."

Felder says of the power ballad: "I believe that if it was written and recorded today, it would fit right in and not be considered a 'dated' sound in any way."

This week, pop star Kim Petras released a very well-timed cover of 'Running Up That Hill' exclusively on Prime Music for Pride Month.

Watch 'Stranger Things' season four, volume one on Netflix now. Volume two arrives on July 1.