Fionn Whitehead as Stefan Butler

Craig Parkinson as Peter Butler

Alice Lowe as Dr. Haynes

Asim Chaudhry as Mohan Thakur

Will Poulter as Colin Ritman

Tallulah Haddon as Kitty

Catriona Knox as Leslie

Paul Bradley as Robin

Jonathan Aris as Crispin

A.J. Houghton as Young Stefan

Fleur Keith as Mum

Laura Evelyn as Pearl Ritman

Alan Asaad as Satpal

Suzanne Burden as Judith Mulligan

Jeff Minter as Jerome F. Davies

Sandra Teles as Reporter

Rochenda Sandall as Pippa 1st AD

Ellie Piercy as Receptionist

Tom McCall as Paramedic

Jon-Jo Inkpen as Pax

Stephen Rashbrook as Narrator