Nico Mirallegro, Will Attenborough, Amy-Leigh Hickman, Georgie (Michelle Keegan) faces her darkest demons when she returns to Afghanistan, alongside new recruits and trainee medic Mimi. A suicide attack instigated by an old nemesis causes questions to be raised about Georgie's future in the army, but with her career hanging in the balance, will her instincts be trusted?