The evolving relationship between Siegfried Sassoon and Wilfred Owen serves as a focus for this history of Craiglockhart Military Hospital and the treatment of shell-shocked officers. The experiences of other soldier patients, such as Max Plowman and George Bonner, are also depicted, together with the methods of their therapists, W.H.R. Rivers, Arthur Brock and William Brown. However, the subject matter is not novel as biographies have been written on both poets and Rivers. Much has been published on the nature of shell shock, its relationship to PTSD and how doctors in World War One sought to return those traumatised by combat to frontline duty. Craiglockhart Military Hospital, though small compared with the Maudsley or Royal Victoria Hospital at Netley, has attracted disproportionate attention, being the subject of two commercial films, Regeneration and Benediction.

What then does Charles Glass add to what appears to be a topic exhaustively explored? First, he provides an insightful and carefully researched narrative into the battlefield experiences of Owen and Sassoon, their breakdown, treatment and use of poetry to understand the trauma of conflict. Glass also brings to life the regime at Craiglockhart, and the challenges faced by the doctors who were subject to competing military and therapeutic imperatives.

The title of the book is a reference to the evidence given by Robert Graves to Sassoon's medical board called to assess his mental state in the light of an anti-war declaration published in The Times. Because of his public profile and Military Cross, the War Office could have managed his protest by finding him insane and committing him to an asylum. Swayed by Graves’ testimony of mental and physical exhaustion, the board preferred a diagnosis of shell shock and sent Sassoon to Craiglockhart.

This is not a book about the representative soldier passing through the standard medical system; Glass describes exceptional patients in an experimental institution. Sassoon, a recognised poet with political connections, was given latitude, choosing to remain aloof from much of the hospital's activities apart from regular sessions with Rivers. Owen, then unknown, was fortunate to be referred to Craiglockhart. There he was allocated to Arthur Brock, whose treatment regime – derived from tuberculosis rehabilitation – dovetailed with Owen's vulnerabilities. Glass contrasts the 758 officers (42%) returned to duty from Craiglockhart with the 7.1% from D Block at Netley. Yet this is not a like-for-like comparison as D Block was a secure unit that treated soldiers diagnosed with severe psychoses, whilst Craiglockhart admitted officers suffering from post-traumatic illnesses, some with established coping skills.

One point of detail: Rivers and Brock are both described as psychiatrists, though neither had formal qualifications in the speciality, nor had they acquired clinical experience in a mental health unit before the war. Brock was a general practitioner who had worked in a tuberculosis sanitorium and Rivers, a Cambridge academic, had research interests in neurology, experimental psychology and anthropology. Yet they undoubtedly developed expertise in the treatment of post-traumatic illnesses, earning the respect of their officer patients. This book is recommended not only to psychiatrists but also to those with an interest in the complex relationships created by war and the management of trauma.