Here's a preview video and the synopsis for American Horror Story: Coven Episode 3 - "The Replacements."

“Over 300 years have passed since the turbulent days of the Salem witch trials and those who managed to escape are now facing extinction. Mysterious attacks have been escalating against their kind and young girls are being sent away to a special school in New Orleans to learn how to protect themselves. Wrapped up in the turmoil is new arrival, Zoe (Taissa Farmiga), who is harboring a terrifying secret of her own. Alarmed by the recent aggression, Fiona (Jessica Lange), the long-absent Supreme, sweeps back into town, determined to protect the Coven and hell-bent on decimating anyone who gets in her way.”

American Horror Story: Coven – Episode 3: “The Replacements” - “Fiona takes on an unlikely protégé. A guilt-ridden Zoe tries to give Kyle his old life back. Madison has a fiery exchange with Joan Ramsey, a new neighbor. Written by James Wong; directed by Alfonso Gomez-Rejon.”