Warning: This article contains spoiler about Stranger Things season 4.
Welcome back, Papa.
After two seasons of being presumed dead after facing the wrong end of a Demogorgon in season 1, Dr. Martin Brenner (Matthew Modine) is back in action in Stranger Things season 4. (Remember, we never actually saw him die in the first season.)
This is apparent from the opening scenes of the new season, which debuted Friday on Netflix. In it, we first see Dr. Brenner via flashback getting ready for work at the Hawkins National Laboratories. The date is Sept. 8, 1979, which is several years before the events of the first season. We see him conducting various tests on the young subjects who possess psychokinetic abilities at the lab, including a very young and tiny Eleven (Millie Bobby Brown).
During a test with Ten, something goes terribly wrong. Ten sees images of blood smeared all over the facility. Suddenly there's lots of screaming. Dr. Brenner goes to investigate and finds blood and bodies everywhere — it seems the nurses and test subjects alike were all killed, except Eleven, who has clearly used her powers and is visibly upset. He asks her repeatedly, "What have you done?!" as the screen fades to black and takes us right into that great opening synth theme.
Netflix Matthew Modine as Dr. Brenner in 'Stranger Things'
Flashbacks aren't the only place Dr. Brenner shows up, though. Later in the season, when it becomes clear that Eleven and her powers will once again be needed to save the residents of Hawkins from an otherworldly threat, Dr. Owens (Paul Reiser), who helped Eleven and the Byers family safely leave town and get settled in California at the end of last season, finds El and convinces her to come with him to try to get her powers back.
What he neglects to mention, however, is that he's working with Dr. Brenner in a top-secret underground facility. Turns out, the rumors suggesting he survived the Demogorgon attack are true, although it's not explained how or shown here. Can El trust him? "Let us work together again, you and I, daughter and Papa," he tells her. It doesn't seem like she has any other choice, and time is quickly running out for her and her friends.
Throughout the last few episodes of season 4, Dr. Brenner, Dr. Owens and El work together to get her powers back. Dr. Brenner's theory is that she lost her powers during the battle at Starcourt Mall in a similar manner to how a stroke patient's neural pathways get cut off — basically, her powers are still there, somewhere, but her access to them has been cut off from the trauma. He believes she can access them again with the right stimuli. So, he puts her in a tank and hooks her up to a machine, trying to get her to remember the events leading up to Sept. 8, 1979 — the gruesome scenes in the beginning of the season.
Despite being the main antagonist of season 1, these interactions allow for some surprisingly tender moments between Papa and daughter. Maybe he's not so bad after all? After two seasons of being mostly non-existent, Dr. Brenner played a surprisingly important role in season 4. Although the full fruits of their labor to revive El's telekinetic prowess are not revealed through the season's first seven episodes, it does pave the way for what should be an epic showdown in the supercharged final two episodes dropping July 1.
Sign up for Entertainment Weekly's free daily newsletter to get breaking TV news, exclusive first looks, recaps, reviews, interviews with your favorite stars, and more.