Eleven shows up and kills the monsters trying to get in the house.
Everyone comes up with a plan to close the gate to the Upside Down. Hopper and Eleven go to the lab to close the portal up.
Everyone else manages to get rid of the virus from Will by overheating him.
Mike, Dustin, Lucas, Steve, and Max hit up the tunnels to get the pack away from the lab and Dart helps them out.
Max sedates Billy when he lashes out at Steve.
Eleven unleashes her power and kills all the monsters in Hawkins and closes the gate in the process.
Barb is given a proper funeral and Owen provides birth certificates for Eleven.
In the upside down, the Shadow Monster is still alive and is ready to attack the school.