Once you get in, you can't get out.
Four teenagers at a British private school secretly uncover and explore the depths of a sealed underground hole created decades ago as a possible bomb shelter.
Thora Birch
Liz Dunn
Desmond Harrington
Mike Steel
Keira Knightley
Frances 'Frankie' Almond Smith
Laurence Fox
Geoff Bingham
Embeth Davidtz
Dr. Philippa Horwood
Steven Waddington
DCS Tom Howard
Emma Griffiths Malin
Daisy
Kelly Hunter
DI Chapman
Daniel Brocklebank
Martyn Taylor
Jemma Powell
Minnie (as Gemma Powell)
Gemma Craven
Mrs. Dunn
Anastasia Hille
Gillian
