Mia Goth

as Mabel (voice)

Matthew Goode

as Raymond (voice)

Claudie Blakley

as Penelope (voice)

Eleanor De Swaef-Roels

as Isobel (voice)

Mark Heap

as Mr. Thomas (voice)

Stephanie Cole

as Great Aunt Eleanor (voice)

Miranda Richardson

as Aunt Clarice (voice)

David Peacock

as Uncle Lucien (voice)