On The Magicians Season 4 Episode 9, a hedgewitch terrorist group that calls themselves The Serpent is trying to control the number of hedgewitches that are using ambient magic via a blood worm that will kill its host. Kady is set to team up with Pete to investigate, but then Alice swoops in asking for Kady's help.
But there are bigger fish to fry. Zelda is trying to get Harriet out of the mirror world and it's not going well when they discover that Harriet has been shattered into three pieces. Using some magic Alice is going to attempt to put Harriet back together but not before splitting herself in two and learning some hard lessons.
Quentin, Julia, and Penny start off on the quest for the mysterious Binder that the East River Dragon told Julia to find. However, their plans are derailed by the Monster, who has discovered a psychic hotline. The Monster intends to use the psychics to prob his memory to try to unlock what happened to him. However, most psychics are too weak to go up against him. So Penny volunteers under the logic that he had the beast in his head.
Meanwhile, in Fillory, news has finally reached Margo that Elliot is alive, but Fen is still coming to terms with her destiny. Margo thinks she may have a way to save Eliot but may have to give up her crown to do it.