Stranger Things Season 02 episode 8

 Stranger Things' sixteenth episode, "The Mind Flayer," is the eighth of the show's second season. Together with the remainder of the season, it debuted on October 27, 2017.When a lethal development forces the Hawkins Lab into lockdown, keeping Will and numerous others within, an unlikely hero steps forward.

A young demogorgon confronts Jim Hopper; Sam Owens assures him that the glass between them will not shatter. When multiple more join it, the glass starts to break, sending everyone in the room running. When the remaining scientists take the lift and are killed by the demogorgons, who use it to access the lab's upper levels, Owens locks down Hawkins National Laboratory and follows Hopper up the stairs. Since the shadow monster can detect where they are using Will Byers, Mike Wheeler is adamant that he be put under sedation. When Will falters in admitting who she is, Joyce Byers sedates him despite his furious objections. Hopper and Owens show up right before the demogorgons explode.

Emerging from the tunnels is an army of Demodogs that starts to infiltrate the remainder of Hawkins Lab. When Mike, Joyce, Hopper, Bob, and Doctor Owens discover that Will is being targeted by the aliens, they sedate him to confuse them.

When the power goes out, a catastrophic systems failure traps them in a security office on the top floors, giving the creatures full reign to roam the building. Being more tech-savvy than Hopper, Bob offers to walk outside and restart the systems that are required to bring the electricity back. Owens stays behind and directs the others out using the security cameras. Hopper, Will, Mike, and Joyce manage to flee, but Bob is slain by the Demodogs. Dustin proposes that the Shadow Monster is a Mind Flayer as the gang retreats to the Byers' home. They hide their whereabouts and question Will. In Morse code, he taps out "CLOSE GATE." Will becomes aware of his whereabouts when the house phone rings. A Demodog is sent by The Mind Flayer.