Scott Grey is a military nurse in the Queen Alexandra's Royal Army Nursing Corps and member of the Medical Emergency Response Team (MERT) at Camp Bastion in Afghanistan. His fiancée, Naomi Scarlet, a Royal Army Medical Corps Combat Medical Technician is out on patrol with The Royal Regiment of Scotland on a mission to secure and destroy a Taliban arms cache. Both are trying to put behind them the horrors they witnessed in Iraq, on this their second tour of Afghanistan. Naomi's patrol comes under attack from a Taliban sniper, one soldier dies and another is injured before he can be suppressed. The wounded soldier requires immediate evacuation by helicopter with the trauma team of surgeon, nurse and two medics on-board to work on him before surgery at Camp Bastion Hospital. Whilst they are scrambled Naomi keeps him alive with battlefield first aid, unaware that Scott is on-board the Chinook rushing to their aid. Their presence is felt by the Grey Lady ghost of the Cambridge Military Hospital which closed in 1996 and is being refurbished into flats. In life and now death she was a Nursing Sister of the Queen Alexandra's Imperial Military Nursing Service during the First World War. For decades she helped dying patients find comfort and brought them to their loved ones on the other side, often felt and occasionally seen by living nurses. She now waits for her new patient, Scott, a fellow QA, though now they are named the QARANC. After their traumatic experiences in Afghanistan Scott buys a flat in Aldershot, on the site of the former CMH and tries to settle down to work at the Ministry of Defence Hospital Unit Frimley Park. However he has health issues after a head injury sustained during a MERT evacuation that still affects him emotionally and physically. He starts to see visions of the Grey Lady ghost who takes him to a Casualty Clearing Station in France during the Great War and to the trenches as the Battle of Loos commences. Here the Grey Lady's fiancé, Hugh, goes over the top with his regiment, The Gordon Highlanders. Though he survives, he is badly injured and becomes a patient at the CMH, where he has to keep his love for the Nursing Sister secret because her Matron will discharge her from the army: nurses in those days could not commit to their vocation and a husband. Scott and Naomi fear that the Grey Lady will part them and need to lay her to rest by letting her tell her story through Scott to its tragic end. Only then, they hope, will her haunting cease.