Detailed Explanation
The revelation that Ms. Casey is Gemma was one of the most gut-wrenching twists I've seen on television. Gemma supposedly died two years before the show begins, but her body was never found. Lumon clearly recovered her and severed her, creating Ms. Casey—a wellness counselor who has no memory of her life as Mark's wife. The implications are horrifying: How many other "dead" people has Lumon harvested? What are they really doing on the severed floor? And will outie-Mark ever learn his wife is alive in the same building?