On the day before Thanksgiving, thousands of fans of the hit Netflix series Stranger Things waited excitedly in front of their screens for the anticipated release of the first few episodes of Season 5. However, with more than three years passing since the previous season came out, many viewers found themselves struggling to remember the details of the series, including monsters and storylines of the Upside Down. If you’re anything like them, consider this your quick refresher to prepare you for the rest of the season coming out later this year.

Spoilers ahead for Seasons 1-4 of Stranger Things

Season 1:

The season introduces a group of middle-school boys named Mike, Will, Lucas, and Dustin  in the year 1983 in Hawkins, Indiana. On his way home, one of the boys, Will Byers, disappears, presumably taken into a parallel dimension called the Upside Down by a ferocious monster, the Demogorgon. While searching for Will in the woods, his friends meet Eleven, who they call El, a girl with telekinetic powers who has escaped a government lab. As Will’s mother—Joyce—and chief officer Hopper search for Will, the boys and Eleven confirm that Will is trapped in the Upside Down. Meanwhile, Nancy—Mike’s sister—and Jonathan—Will’s brother—develop a close relationship while investigating the behavior and hunting patterns of the demogorgon, with Steve later joining the investigations. It is revealed that Eleven was responsible for opening the portal to the Upside Down in Hawkin’s Lab in one of her memories. In the end, Will is rescued and Eleven defeats the demogorgon, but disappears in the process. The season ends with Will coughing up a slug that appears to be from the Upside Down. 

Season 2:

A year later, Will experiences visions of a massive cloud-like shadow creature in the Upside Down, later known as the Mind Flayer. Unbeknownst to the boys, Eleven lives with Hopper after her disappearance in Season 1, where she learns of her biological mother and her real name, Jane. New characters Max and her stepbrother Billy are introduced. Max gets close with the boys as they search for Dart together, a loose demodog in Hawkins. After many visions of the Mind Flayer, Will eventually gets possessed by it, revealing hundreds of tunnels below Hawkins to Joyce and Hopper. Meanwhile, Nancy and Jonathan work with conspiracy theorist Murray to take down Hawkins Lab for its mistreatment of children. The season ends with a demodog attack led by the Mind Flayer on Hawkins Lab, with El returning to finally close the portal to the Upside Down. Despite the gate closed, the season ends ominously, with the Mind Flayer looming over Hawkins in the Upside Down.

Season 3:

Summer 1985 at Hawkins brings the new and impressive Starcourt Mall, along with secret Russian operations beneath it. When Dustin stumbles across a secret Russian broadcast, he, Steve, Robin—Steve’s coworker—and Erica—Lucas’s brother—discover that Russians have been using a powerful machine to reopen the gate to the Upside Down below Hawkins. Meanwhile on the surface, Billy has been possessed by a small remnant of the Mind Flayer, leading him to kidnap Hawkins citizens to feed the growing creature. Once the kids discover the threat of the Mind Flayer, everyone reunites at Starcourt Mall to take it down, with Billy sacrificing himself and El barely surviving after a piece of the Mind Flayer gets into her body and makes her lose all her powers. Realizing that the Russian weapon must be destroyed in order to close the portal, the adults venture to destroy it, and Hopper is presumed to have died destroying it. The season ends with the Byers family and El moving out of Hawkins, and Russians feeding prisoners to a familiar creature, the Demogorgon.

Season 4:

In 1986, the original Hawkins crew has split. In California, El is taken by authorities after lashing out at a bully, but she is intercepted by Dr. Owens, the new head of Hawkins Lab, who brings her to the Nina Project to restore her powers. Meanwhile, in Hawkins, teenagers experience hallucinations before dying in gruesome ways after being targeted by Henry Creel, or Vecna, a killer of the Upside Down who preys on the trauma of his victims. Back in California, El has regained her lost powers after recovering her past and escapes the Nina Project base with Jonathan, Mike, and Will. Once the Hawkins crew realize that gates to the Upside Down have opened at the murder sites of the teenagers, they start planning to finally kill Vecna. Their final plan consists of distractions in the Upside Down, attacks to Vecna’s physical body, weakening Upside Down creatures, and protection through El’s powers, which together significantly injures Vecna. However, with Max still becoming the final victim and falling into a coma, the final season ends with a massive four-part portal to the Upside Down tearing through Hawkins, the beginning of the end.

This concludes a short recap of Stranger Things Seasons 1-4. As the last season of this franchise arrives, these events ultimately set the stage for final confrontation with the Upside Down. For those who would like a detailed video recap before the finale, one can be found here.