On Halloween, while going through a Stephen King phase, Adam decides to write his own horror story about his over-bearing mother. After Beverly reads it and learns it is about her, she walks into his room with a meat tenderizer while Adam is dressing up as Pennywise from "It". Adam freaks out and begs her not to hobble him, a reference to Misery in which the main protagonist, Annie Wilkes uses a sledgehammer to break captive and bedridden author Paul Sheldon's ankles with a post placed in between them. However, this scene only happens in the 1990 released movie [In the Stephen King novel "Misery", Anne cuts off his foot with an ax and cauterizes the severed area with a heated iron and sterilizes it with iodine] and the series takes place sometime in the 1980's. The film has not been made yet.
Adam dresses as the Tim Curry version of Pennywise from the It mini-series, which premiered in 1990.
Takes place over Halloween, yet all trees/bushes are still fully green and characters are dressed for warm weather. Show takes place in Pennsylvania, so that is not possible.
Adam says he added his middle initial to his manuscript to distinguish himself from another Adam Goldberg who is in 11th grade. In the prior episode ("Crazy Calls") this other Adam was said to be a senior.