Stranger Things Season 5: Hopper’s proposal scene nods to the show’s earliest mystery

Netflix dropped the last episode of Stranger Things Season 5 on December 31, 2025. Titled 'The Rightside Up,' it runs just over two hours.

The Hawkins crew goes all in against Vecna, fighting to keep their world from getting swallowed up by the Abyss. A lot is going on emotionally, too, but one moment really got fans talking: Chief Jim Hopper gets down on one knee at Enzo’s and asks Joyce Byers to marry him. He even lays out his plan: They will move to Montauk, New York, where he will take a job as police chief, and they can finally start fresh together.

The Stranger Things Episode wraps up with Hopper and Joyce talking about moving to Montauk. At first, that detail probably slips right by most viewers. But if you have been watching the show for years or know a bit about its backstory, the Montauk reference hits differently.

The Duffer Brothers tucked it in as a tribute to the conspiracy theory that sparked the whole idea for Stranger Things. So when Montauk gets a mention, it ties Hawkins back to the urban legend from the ’80s that first got everyone's imagination going.

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Stranger Things Season 5: The Montauk connection

What do you need to know about the Montauk Project?

It is a conspiracy theory purporting that the United States government carried out a series of top-secret projects at Camp Hero or Montauk Air Force Station in Montauk, New York. It centered on psychological warfare techniques and metaphysical studies like time travel. The theory emerged in the early 1980s through the books of Preston Nichols and Al Bielek, who said that they had repressed memories of having participated in these secret experiments.

The conspiracy theory states that during the period between 1971 and 1983, the government carried out mind control experiments, time travel research work, and interdimensional exploration in the then-abandoned military base. The claims state that at the Montauk Air Force Station, experiments were conducted concerning kidnapped teenagers, in which they were subjected to different types of psychological experimentation. The so-called ‘Montauk Boys’ would eventually be a direct influence on characters such as Eleven and the rest of the test subjects in Hawkins National Laboratory.

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The Philadelphia Experiment Foundation

The conspiracy theory of the Montauk Project did not appear in a vacuum. Advocates believe that the invisibility and manipulation of space-time study did not conclude with the Philadelphia Experiment and only preconditioned the more sophisticated experiments that were to be carried out at Montauk. The Philadelphia Experiment is a presumed military experiment of October 28, 1943, that was performed on the USS Eldridge.

Notably, Carl M. Allen was a merchant mariner who reportedly said he saw the Philadelphia Experiment back in 1943. Years later, in 1956, he wrote letters to UFO writer Morris K. Jessup, describing what he had witnessed. According to Allen, the Navy installed special equipment in the ship that would generate strong electromagnetic fields and make the ship invisible to enemy radar. But the experiment was reported to have gone disastrously awry.

The experiment rendered Eldridge invisible to some witnesses, stating a “greenish fog” formed where the ship had been, and on reemerging, some of the sailors were found entangled in the metals of the ship. It is alleged that the USS Eldridge not only vanished but also teleported from Philadelphia to Norfolk, Virginia (more than 200 miles) and returned to its starting point.

The crew is said to have endured truly hideous effects such as insanity, physical amalgamation of the steel structure of the ship, and even vanishings. Although the U.S. Navy has thoroughly dismissed such occurrences and the history indicates the USS Eldridge had never been in Philadelphia at the supposed period, the legend lives on in popular culture.

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Stranger Things: The First Shadow and the Philadelphia Experiment

The parallel between Stranger Things and these conspiracy theories is also made even more explicit in Stranger Things: The First Shadow, the Stranger Things prequel, a musical, which opened in the West End in London in December 2023 and on Broadway in April 2025. They sat on their seats with a black screen on the stage with the words Philadelphia Experiment written on it, instantly creating a link between the play and this well-known occurrence.

Now, Stranger Things: The First Shadow drops a big reveal suggesting that back in 1943, the U.S. ran secret experiments with the USS Eldridge under something called Project Rainbow. They wanted to hide the ship from the Germans using electromagnetic fields. However, the ship ends up in Dimension X, a dark, ancient realm. A Demogorgon shows up and wipes out almost everyone on board. Only the captain makes it out alive, and turns out, he is Dr. Brenner’s father.

This whole story changes how you see Stranger Things. It shows that the connection to Dimension X didn’t start with Will Byers in 1983. It has been around for decades. The older Brenner subsequently told the truth of these happenings on his deathbed, and Dr. Brenner later set up the Nevada Experiment, an endeavour to repeat in another what had been seen to befall the Eldridge.

This discovery is what makes Brenner so fascinated with interdimensional studies, and why he was not hesitant to test his hypothesis on children. He was just doing what his father did, trying to comprehend and manipulate the gateway his father had opened mistakenly.

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The way the play relates to Stranger Things Season 5

The Broadway show is a must-watch when it comes to comprehending the last Episodes of Stranger Things Season 5. In the play, Henry goes to a cave in Nevada on his eighth birthday, and he comes back without any recollection of what happened. The cave has technology that is alleged to assist in replicating the Philadelphia Experiment.

This cave, in which a young Henry Creel was put into contact with the particles of Dimension X (which subsequently turned out to be separate from the Upside Down), is the reason why Vecna is afraid of the cave that he can see in his memories in Stranger Things Season 5.

The First Shadow shows that in 1959, the Creel family relocated to Hawkins, where tormented Henry, who already possessed the dark power, fell in love with the young Patty Newby. The play confirms that the powers of Henry and his relationship with the Mind Flayer were not the result of Dr. Brenner’s experiments in the 1950s and 1960s, but it happened as a result of the exposure of Henry to the modified technology in that Nevada cave, which had been compromised by Soviet spies during the Cold War period.

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How does Hopper’s proposal relate to all this?

The reference to the Montauk in the proposal scene by Hopper is a poetic end to the Stranger Things journey. What was initially a series based on a Cold War-era conspiracy theory of hidden secret government experiments, mind control, and interdimensional travel ended by actually recognizing those origins.

Hopper and Joyce, two characters with an unimaginable history of trauma, having had to fight Demogorgons and survive Russian prisons, finally receive a happy ending of leaving Hawkins behind and heading to the place where the mythology of the show was first born.

The Stranger Things finale confirms that the father of Brenner was directly connected to the Philadelphia Experiment, and his survival of this experiment led to all events that followed. The Duffers used the reference to Montauk in the finale to close a narrative circle and admit that the fight with Vecna might be ended, but the legacies of these initial experiments will always remain a part of their lives.