In the small town of Hawkins, Al and Max are anxiously searching for signs of Billy, while Will declares that he will live a girl-less life and enjoy his own time.Steve and Dustin were tasked with monitoring the town for unusual activity, while Joyce and Hopper returned to Hawkins Laboratory, hoping to find more clues about the Mind Flayer there.

After Eleven broke up with Mike, she felt deeply about her impulsiveness and recklessness.She decided to use her superpowers to monitor Mike again, but unexpectedly found that his behavior had become extremely childish, as if he had returned to his teenage years.This confused and disturbed her.Therefore, Eleven and Max decided to use Billy as a new target and use super powers to reveal his true face.

However, the results of this surveillance were horrifying.Eleven witnessed Billy kidnapping lifeguard Heather and heard her screams.Back at Max's house, they find a bathtub filled with melted ice packs and a blood-stained lifeguard whistle, clues left behind by Billy.

Meanwhile, other parts of the city are conducting their own investigations.At the Star Court, Steve, Dustin, and Robin discover coded words in a Russian message that relate to various locations in the mall.Nancy seems to have discovered something, but her discovery was ignored by editor Tom.In order to avoid being fired, Jonathan followed Nancy to investigate, but accidentally discovered Mrs. Driscoll's abnormal behavior of eating fertilizer like a crazy mouse.

Hopper ventured into the blocked Hawkins Laboratory, trying to prove to Joyce that those who endangered Will had left.After an earlier argument, they have an affectionate conversation in which Hopper admits that he has been trying to make Joyce feel safe, and Joyce reveals her plans to leave town.Just as they realize they are not alone, Hopper is ambushed by the mysterious Russian Grigory.

As Will rides his bike home in the rain and passes Byers Castle, he feels a strong presence of the Mind Flayer.In anger, he destroyed the castle.Later, when Mike and Lucas arrive to apologize, Will tells them that the Mind Flayer has returned.

Eleven and Max continue their detective work, only to discover that Heather is not at the pool as usual.They find Billy and Heather at Heather's house, only to find that they are having dinner with Heather's parents, one of whom turns out to be Nancy's boss Tom.Billy tries to act normal and tries to get the two girls to leave.However, Heather's parents began to fear that they were the Mind Flayer's next targets.