Emilia Fox Dr Nikki Alexander Actor David Caves Jack Hodgson Actor Richard Lintern Dr Thomas Chamberlain Actor Liz Carr Clarissa Mullery Actor Ben Bailey Smith Lieutenant Colonel Ben Carmichael Actor Dan Parr Edmund `Fish' Fishbourne Actor Michael Simkins A.C. Harry Lennox Actor Ash Tandon D.I. Karl Guyatt Actor Caroline Lee Johnson Sandra Gibbs Actor William Ash Major Mark Sealy Actor Richard Durden Conor Hodgson Actor Graham Turner Arthur Simpson Actor Tina Chiang Simone Taylor Actor Will Stevens Private John Sealy Actor Daniel Weyman Max Thorndyke Actor Julia Haworth Rosie Chamberlain Actor Michael Crompton Writer Dominic Leclerc Director Richard Stokes Executive Producer Lawrence Till Producer