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.
Liz Dunn
Mike Steel
Frances 'Frankie' Almond Smith
Geoff Bingham
Dr. Philippa Horwood
DCS Tom Howard
Daisy
DI Chapman
Martyn Taylor
Minnie (as Gemma Powell)
Mrs. Dunn
Gillian
Policewoman
Solicitor
Boy in School
Doctor
Reporter
