Ralf Little Richard Actor, Writer Michelle Terry Sarah Actor, Writer 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 Mackenzie Crook Guest Star Craig Cash Director