Ralf Little Richard Actor, Screenwriter Michelle Terry Sarah Actor, Screenwriter June Watson Mary Actor Ellie Haddington Carol Actor Daniel Ings John Actor Phoebe Waller-Bridge Chloe Actor David Troughton Stan Actor Seeta Indrani Brenda Kelly Actor Carolin Stoltz Ava Actor Brian Murphy Mr. Dobson Actor Marcia Warren Mrs. Dobson Actor Craig Cash Director, Executive Producer Lucy Ansbro Executive Producer Susie Liggat Producer