Emmy-nominee Kathryn Hahn reprises her role as Agatha Harkness for a brand new Disney+ Marvel series launching later in 2024. Agatha: Darkhold Diaries will reveal more about the character first introduced in Marvel Studios’ WandaVision. Jac Schaefer, who served as head writer and executive producer on WandaVision, returns for Agatha: Darkhold Diaries.