Kathryn Hahn chats with ET’s Cassie DiLaura about ‘Agatha All Along,’ debuting Sept. 18 on Disney+. The actress reacts to getting to perform ‘The Ballad of the Witches’ for fans at the 2024 D23 Expo. Kathryn also opens up about diving into Agatha’s story in the series after introducing her in ‘WandaVision.’ Plus, she plays coy about whether Elizabeth Olsen, who portrays Wanda Maximoff, could make an appearance in the show while gushing about their friendship.