Jack and Strickland form an unlikely alliance that sees them break the rules to find out why a British soldier died while taking part in a Ministry of Defence medical trial. With three of the man's colleagues now suffering from psychological, drink or memory problems, the team consider whether he died as a result of the experiment, or if he was a victim of an Army cover-up.

• Nigel McCrery

• Frances Barber
• Georgina Rylance
• David Bamber