Guest Stars Craig Parkinson as Peter Butler Will Poulter as Colin Ritman Asim Chaudhry as Mohan Thakur Alice Lowe as Dr. Haynes Jonathan Aris as Crispin Fleur Keith as Mum Rochenda Sandall as Pippa 1st AD Tallulah Rose Haddon as Kitty Fionn Whitehead as Stefan Butler A.J. Houghton as Young Stefan Suzanne Burden as Judith Mulligan Catriona Knox as Leslie Sandra Teles as Reporter Stephen Rashbrook voices Narrator Alan Asaad as Satpal Ellie Piercy as Receptionist Laura Evelyn as Pearl Ritman Jeff Minter as Jerome F. Davies Tom McCall as Paramedic Jon-Jo Inkpen as Pax Paul Bradley as Robin