While Mike and El anticipate a reunion in California for spring break, the kids in Hawkins try to navigate the challenges of high school. Max struggles with her brother's loss, and Joyce receives a strange package in the mail.
Mike arrives in California to visit El and the Byers, where a secret message has Joyce convinced the Hopper is alive. Meanwhile Hawkins is rocked by the shocking death of a student, and Max and Dustin try to find Eddie Munson.
While the manhunt for Eddie continues, Eleven is forced to face the consequences for her actions – and Joyce goes after Hopper. Robin joins Nancy for an archive search, and Lucas finds himself caught up in Jason's revenge plot.
The kids rally to try and save Max before Vecna's curse kills her, and Nancy and Robin visit a mental institution to talk to a man they think survived the demon three decades earlier. Elsewhere Joyce and Murray arrive in Alaska, while Hopper risks his life to escape the Russian gulag.
The boys flee from government soldiers who are trying to find Eleven, while Nancy finds a clue in Max's experience with Vecna. Meanwhile Eleven arrives at a facility where she hopes to recover her powers, but receives an unexpected surprise.
El determines to work with Dr. Brenner to recover her powers, while Mike's group seeks help from Suzie to track down Project Nina. The people of Hawkins are riled up by another death, and Joyce and Murray strike out across the frozen wilderness to find the prison.
As Steve, Nancy, Robin, and Eddie search for a way out of the Upside Down, Eleven remembers the terrible incident that took place at Hawkins Lab and the part she played in it. Joyce and Murray arrive at the Russian prison with a crazy plan to try and free Hopper.
While Eleven comes to terms with her abilities and what's at stake, Joyce and Hopper look for a way to escape the Soviet gulag. Vecna sends Nancy back with a terrifying message, leading the group to plan for a dangerous last stand.
With Max attempting to lure the enemy into a trap, Steve and Nancy lead a group into the Upside Down to take out Vecna. Eleven enters the astral plane to try and help them, and Joyce and Hopper decide to break back into the prison.