Forever alone in a crowd, failed comedian Arthur Fleck seeks connection as he walks the streets of Gotham City. Arthur wears two masks -- the one he paints for his day job as a clown, and the guise he projects in a futile attempt to feel like he's part of the world around him. Isolated, bullied and disregarded by society, Fleck begins a slow descent into madness as he transforms into the criminal mastermind known as the Joker.
It’s the fall of 1984, about a year after Will Byers was found, and he has been plagued by seeing visions of the Upside Down featuring a more dangerous monster. That leads the boy to see a suspiciously friendly new doctor, with the possibility that Will’s visions are the result of suffering from PTSD. Nancy deals with survivor’s remorse over the death of best friend Barb. Meanwhile, a new sinister entity threatens the Hawkins residents who survived the year-earlier events. New to the town is tomboy Max, who befriends the boys and attracts the romantic interests of Dustin and Lucas.
When renowned crime novelist Harlan Thrombey dies just after his 85th birthday, the inquisitive and debonair Detective Benoit Blanc arrives at his estate to investigate. From Harlan's dysfunctional family to his devoted staff, Blanc sifts through a web of red herrings and self-serving lies to uncover the truth behind Thrombey's untimely demise.