Chief Hopper's death in Season 3 is one of the most profound moments in the show. It has left fans still unable to accept that he is gone. So much so, that they have come up with various theories to suggest that he is still alive in "Stranger Things" Season 4.
One fan particularly analysed past seasons to find clues that point to Hopper's fate in Season 4. One such clue is found in Season 1, after the town of Hawkins was hit with the massive news of Will Byers' death. After an arduous search, his lifeless body was ultimately found in the local quarry.
According to the fan, the music played over that particular scene, when the police fished out Will's body, was Peter Gabriel's cover of "Heroes." It is the "exact same song" played at the end of Season 3 after Eleven read Hopper's letter for her.
"Everyone thought Will was dead, BUT HE WASN'T. Why use exactly the same music? Because, like Will, Hopper's not dead," the fan wrote on Reddit.
In Season 1, Chief Hopper's instincts told him that Will is still alive. So, he went to the morgue and cut through the boy's body to discover that it was fake. Will was in the Upside Down after all.
There have been a lot of theories that suggest Hopper is still alive in "Stranger Things" Season 4. One is that he is the American captured by the Russians at the end-credits scene in Season 3. Another is that he is alive but stuck in the Upside Down after he escaped the explosion. This would reportedly connect to his reminder to Eleven that she should "keep the door open 3 inches" for the sake of her "poor old dad." This supposedly is already a hint that Hopper is coming back.
Likewise, showrunners The Duffer Brothers have not confirmed that Hopper is dead. They only reminded the viewers to remember that if there is no corpse, then there is no proof of death. The same situation applies to Hopper and to Dr. Martin Brenner, who was also presumed dead in Season 1, when the Demogorgon attacked him. Until there is a real corpse, fans can keep their fingers crossed that Hopper is alive in "Stranger Things" Season 4.