Stranger Things 5 is one of the most anticipated TV series of 2025. While fans are counting down the days to see how the story unfolds, a shocking theory is circulating online predicting that Will Byers was actually a test subject at Hawkins National Laboratory.

Netflix will unveil the final season in three parts. Part 1 will drop on November 2025, followed by Part 2 on Christmas Day, and Part 3 on New Year’s Eve. With the story coming to a close, it is expected that there will be unexpected twists. Some Stranger Things fans believe that Will Byers has a deeper connection to HNL.

Were Will Byers and Sara Hopper Test Subjects at HNL?

We all remember that Will Byers was abducted by the Demogorgon in season 1 and how Joyce Byers and Jim Hopper rescued him. But even after his return, Will Byers still had some connection with the Upside Down as he continued to experience visions involving the Demogorgon.

Now, a fan has come up with a theory that Will Byers and Sarah Hopper (Jim Hopper’s daughter who died of cancer) were test subjects at HNL. While it might sound crazy, there are some subtle clues throughout the series.

In season 1, Hopper was seen crying in the corner of a stairwell. Then in season 2, Eleven and Hopper were shown entering Hawkins’ Lab to close the gate. They saw Dr Owens bleeding in the very same stairwell. It confirms that both of these locations are the same.

When David Harbour was asked by Business Insider about the connection between Sara’s death and HNL, he said

“Hmmmm [laughing] I can not. But yes, it is the same location. So that’s interesting. Or it’s a similar location.

Hidden Connection Between Eleven, Will and Sara

He also pointed out another interesting clue during the interview.

“But there’s actually another thing you’ll notice which is that there’s a stuffed animal lion that appears in Eleven’s room when he breaks into the lab and finds that room, and it also appears in Castle Byers, and it also appears on Sara’s lap.”

Harbour’s confirmation of the link between these three animals suggests that Sara and Will Byers could also be the test subjects at the lab.

The same stuffed animals in three different locations? Not a coincidence.

He further revealed to Business Insider that nothing is done randomly in the show and it will pay off in the end.

“So yes — there is a connection there perhaps that we may go into further down the line. Again these are little things that highlight mysteries that I don’t want to give too much away from but I don’t think anything is done randomly in this show. So the fact that you’re picking up on these things is something that will pay off in some way.”

In season 1, Eleven was able to recognize Will Byers just by looking at a photo, even though she had never met him. Another clue that stands out is that the lab was able to create an exact copy of Will’s body to hide the fact that he was trapped in the Upside Down due to their fault. The fake body even had a birthmark on its arm.

If Will Byers was actually a test subject at HNL, it could explain why he is connected to the Upside Down. If that is the case he might even have he might have superpowers just like Eleven.

What makes this theory even believable is that an actress has been cast to play Sara Hopper in season 5. It means that she will be seen in flashbacks and could be part of a major twist in the final season.

Could Will Byers have been a test subject at Hawkins National Laboratory? Will season 5 finally uncover the hidden connection between Eleven, Will Byers and Sara Hopper? Share your thoughts and fan theories in the comments below.