In the eighth episode of the fourth season of Chapter Eight, we see the backstory of Dr. Brenner, aka Papa, the man responsible for the experimentation on Eleven and other children with abilities.

The episode begins with Eleven having a vivid dream where she sees her “sister” Kali, who encourages her to find and confront Brenner. With the help of her friends, Eleven sets out on a mission to find Brenner, hoping to get answers about her past.

As they journey through various labs, they eventually come across Brenner, who is presumed dead. They learn that he faked his own death and has been hiding out, continuing his experiments on children with abilities.

Eleven confronts Brenner, demanding answers about her past and the other children like her. Brenner hesitantly reveals that there were others before Eleven, but none of them were as successful as her. He shares his twisted reasoning behind the experiments, claiming that he wanted to create powerful soldiers to win the Cold War.

Meanwhile, we see flashbacks of Brenner’s life, including his relationship with his daughter, who passed away from cancer. It’s revealed that Brenner saw Eleven as a replacement for his daughter, causing him to become obsessed with her abilities and manipulating her.

The episode ends with Eleven rejecting Brenner’s offer to be with him again and ultimately choosing her found family over him. Brenner is arrested, and the children’s abilities are finally acknowledged and validated by the government.

Chapter Eight: Papa is an emotional and revealing episode that sheds light on the dark past of Dr. Brenner and Eleven’s origins. It adds a new level of complexity to the supernatural world of Stranger Things while also showcasing the strength and resilience of Eleven and her friends.