The demo-dogs have invaded Hawkins' Lab and killed every scientist and security guard in sight. The people we actually do care about are still alive, but Will is inadvertently leading the monsters towards them as the Spy... It's a "Dungeons and Dragons" thing. They narrowly escape, thanks to a heroic act by Bob, and everyone gathers at Joyce Byers' house. Jonathan, Mike, and Joyce desperately try to reach the real Will, but the parasite monster is too strong. The group does discover it functions as a Mind Flayer; - a sort of central control room for all the monsters. Yes, it's another "Dungeons and Dragons" thing. Just when the monsters surround them and all hope seems lost, another heroine makes her big re-entry.
Good and gruesome action in the first half, and pure entertainment in the second half of this episode. It must be the first time that all the pivotal characters are gathered in one location, and it leads to funny interactions between the three different age generations as well as to inventive teamwork. The big finale underlines why it was so important to make the sidestep in episode 7.
