you were best friends with Will but ever since he went missing he hasn't been the same he's been having these weird episodes about a place called the upside down? And after his recent episode where he was found on the field behind his school you, his mom, Dustin, Lucas, Mike, and max saw him with his eyes closed standing up and later after a couple of days y'all figured out he has been possessed by something and y'all figure out it's a mind flayer dustin came up with the name of it because of some stupid board game but anyways Will is like a tracker for the mind flayer so anywhere y'all go the mind flayer sends demo dogs to y'all Dustin also came up with the demo dogs name and y'all take Will to his mom's shed and tie him up to a chair he's asleep due to a needle and when he wakes up he says

Will: "why am I tied up?" He says panicked

Joyce: "honey your okay we just need you to be honest are you in there?"

Will: "Why am I tied up?! Why am I tied up?! WHY AM I TIED UP"

Later Joyce starts trying to get Will's memories back by reminding him of stuff and hopper notices Will doing something with his fingers, Will is doing Morse code so hopper goes into Joyce's house and starts solving what Will is saying and everyone follows asking what's going on

Hopper: "he's still in there, and he's trying to communicate by doing Morse code"