It was previously reported that “Stranger Things” Season 4 would have 8 episodes, like Seasons 1 and 3 -- but according to a source, the Duffer brothers have added one more episode into the mix for the upcoming installment of the Netflix series. 

TVLine was the first to report the news of an additional episode for Season 4. The outlet also noted buzz about the extended run possibly including an "origin story" for one of the show's "fan-favorite" characters "in one (or more) of those nine episodes." 

“Stranger Things” Season 2, which also had 9 installments, did something similar with its episode “The Lost Sister.” That episode, which received mixed reactions from fans, focused solely on Eleven's (Millie Bobby Brown) story arc. 

While it remains to be seen which character is getting their own rumored Season 4 origin story, some Twitter users have a theory:

Officer Jim Hopper (David Harbour) is arguably the most talked-about character following “Stranger Things” Season 3 due to his supposed death, which was immediately rejected by fans due to a post-credits scene. The sequence in question took place in Russia and mentions an American prisoner not shown onscreen. Many believe this prisoner to be Hopper. 

As of last fall, “Stranger Things” Season 4 was reported by TVLine to start shooting in early 2020 with plans to wrap production in August. No official release date has been announced.

Stranger Things Eleven (Millie Bobby Brown) and Hopper (David Harbour) in "Stranger Things" Season 3. Photo: Netflix