First broadcast 3rd/4th February 2020.
Thomas investigates the case of John Sealy, a soldier who died during a military training exercise involving exposure to CS gas.
Will Stevens - Pvt. John Sealy
Daniel Stewart - Sgt. Haring
William Ash - Major Mark Sealy
Clare Higgins - Professor Katherine Dukes
Richard Lintern - Dr. Thomas Chamberlain
Ben Bailey Smith - Lt. Col. Ben Carmichael
Robert East - Henry Young
Ash Tandon - DI Karl Guyatt
Dan Parr - Edmund 'Fish' Fishbourne
Richard Durden - Conor Hodgson
David Caves - Jack Hodgson
Emilia Fox - Dr. Nikki Alexander
Adelle Leonce - DS Lucy Vail
Graham Turner - Arthur Simpson
Tina Chiang - Simone Taylor
Julia Haworth - Rosie Chamberlain
Liz Carr - Clarissa Mullery
Daniel Weyman - Max Thorndyke
Elizabeth Boag - Paramedic
Michael Simkins - AC Harry Lennox
Caroline Lee-Johnson - Sandra Gibbs (as Caroline Lee Johnson)
Laura Lake - Book lover
Dan Parr - Fish
Comments