Stranger Things fans realise key moment in the finale was foreshadowed in first episode

Stranger Things fans have spotted a key moment in the newly released season five trailer that's linked to the very first episode.

Stranger Things is coming to an end with season five coming out in parts later this year on Netflix, following up on the apocalyptic-style events in the series four finale.

Despite the gang's best efforts to destroy Vecna, he is only weakened but manages to leave the gates to the Upside Down open, merging the terrifying world with Hawkins.

The trailer, which was released on Wednesday, July 16, teased what's to come with a plethora of dramatic clips as the Hellfire Club and friends fight back.

But it was one particular snippet that stood out among the rest as it was actually foreshadowed in season one's premiere episode nine years ago.

With Hopper's (played by David Harbour) voiceover stating: "I need you to fight one last time", a close-up is shown of Will Byers (Noah Schnapp), whose face seems to be lit up by some nearby flames.

In a dramatic moment, Will closes his eyes like Eleven (Millie Bobby Brown) does when she's using her powers.

Then at the end of the trailer, Vecna is seen being attacked by a tornado of fire, believed to be the Fireball spell.

Taking to Reddit, someone points out: "I think Will [is] casting Fireball on Vecna. He says I cast Fireball in the first episode."

Fireball is a spell from the iconic game Dungeons and Dragons which features in one of the first scenes in Stranger Things' debut episode back in 2016.

The gang are playing when Mike Wheeler (Finn Wolfhard) tells his friends that a Demogorgon is about to attack them all.

Lucas Sinclair (Caleb McLaughlin) pressures Will to conduct the Fireball spell while Dustin Henderson (Gaten Matarazzo) tells him to cast a protection spell instead.

After some moments of hesitation, Will shouts: "Fireball!", rolling the dice which then falls onto the floor.

Responding to the Reddit comment, someone replied: "How do you know these things man I'm jealous of you."

Another suggested: "I think Ell will cast it but Will will call it. I think it's time for him to run the ops, Dungeon Master style", while a third agreed: "They're definitely gonna reference some of that earlier episode DnD stuff."

Stranger Things season five part one premieres on Wednesday, November 26, on Netflix.