Richard Coyle
— Michael Sheldrake
Keeley Hawes
— Kate Sheldrake
Toby Stephens
— Peter Tremaine
Aaron Taylor-Johnson
— Michael Sheldrake (age 15)
George Irving
— Miller
Laura Aikman
— Alison Poley
Indra Ové
— Natalie
Jack Baverstock
— Bruce Miller
Kate Fahy
— Dr. Cowley
Joseph Friend
— Michael - as a boy