To close the gate, Hopper fights off the Russian assassin Grigori, eventually throwing him into the machinery. Trapped on the platform as Joyce turns the keys, Hopper seemingly vanishes in the resulting explosion. An Emotional Farewell
Eleven reaches through the Mind Flayer’s control by reminding Billy of his happiest childhood memory at the beach. Billy then sacrifices himself to save Eleven, standing directly in the monster's path.
Eleven and her friends face off against the massive Mind Flayer "Meat Monster". With Eleven’s powers drained after removing a piece of the monster from her leg, the kids resort to using Lucas’s "Satan's Baby" fireworks to fend it off.
Steve and Robin arrive just in time to save the group by ramming the "Todfather" convertible into Billy’s car. Heartbreaking Sacrifices
The episode's core conflict is split across three main fronts, coordinated by from his "Cerebro" radio tower on the hill: