"Stranger Things" Season 4 may see Dustin, Erica, Steve, and Robin back together following their adventure at the Russian lab in Season 3. This is probably if one of the storylines in the show's spin-off comic book is any indication.
A strip from the comic book shared by CBR.com revealed that Erica Sinclair (Priah Ferguson) has started a side business of selling a dangerous-looking green acid which she somehow smuggled out of the Russian lab in the Season 3 finale. She called up Dustin Henderson (Gaten Matarazzo) and asked him how much it would likely cost to sell the "green canisters" they found at the secret Russian base. Dustin thought she was talking codes at first and referred to the canisters as a bottle of coca-cola and the secret base as the grocery store.
However, he eventually realised what Erica was up to. He gathered Robin Buckley (Maya Hawke) and Steve Harrington (Joe Keery) to plan an intervention. They have to stop Erica's little business. After all, a glowing, green acid retrieved from the Russians who were trying to open the door to The Upside Down obviously means bad news.
It turned out that Erica was only trying to come up with the money to buy a new Dungeons and Dragons book set. She thought she could not borrow them from her friends because they did not own the books. Thankfully, Dustin, Robin, and Steve stopped Erica and the four instead regrouped to play D&D with Erica as the new Dungeon Master.
This plot in the spin-off comic book may not be anything serious but it becomes wishful thinking for fans to see the foursome get together again in "Stranger Things" Season 4. They had such great interplay in Season 3. Erica and Robin were a welcome fun addition to the group. Had it not been for them, Steve and Dustin would not have located the Russian's secret base underneath Starcourt Mall.
Interestingly, the green acid in the comic book seemingly also points at the glowing liquid seen in the Russians' possession in Season 3. Perhaps this is a hint that the substance becomes a major part of the storyline in "Stranger Things" Season 4.