Naomi Watts

as Dr. Jean Holloway

Billy Crudup

as Michael Holloway

Sophie Cookson

as Sidney Pierce

Melanie Liburd

as Alexis Wright

Karl Glusman

as Sam Duffy

Lucy Boynton

as Allison Adams

Poorna Jagannathan

as Larin Inamdar

Brenda Vaccaro

as Claire Rogers

Brooke Bloom

as Rebecca Rogers