England, 1969. The fascinating Abbie and the troubled Lydia are great friends. After an unexpected tragedy occurs in the strict girls' school they attend, a mysterious epidemic of fainting breaks out that threatens the mental sanity and beliefs of the tormented people involved, both teachers and students.
Maisie Williams
as Lydia Lamont
Maxine Peake
as Eileen Lamont
Greta Scacchi
as Miss Edith Mantel
Monica Dolan
as Miss Martha Alvaro
Mathew Baynton
as Mr. Hopkins
Florence Pugh
as Abbie Mortimer
Joe Cole
as Kenneth Lamont
Morfydd Clark
as Miss Pamela Charron
Anna Burnett
as Susan
Hannah Rose Caton
as Titch
Evie Hooton
as Janet
Katie Ann Knight
as Connie
