The Eye in the Door is the second in a series of three anti-war novels written by acclaimed British author Pat Barker. Known collectively as "The Regeneration Trilogy", each of the novels takes place during World War One and features the same central characters at their core, some entirely fictional, others embellished historical figures. This novel begins in the spring of 1918, after the German army has almost annihilated the British troops in the trenches of France; both the British government and its people are baying for blood and in need of someone to blame for the success of the German offensive and two groups seem to be ideal scapegoats - pacifists and homosexuals.
In this climate, Billy Prior, one of the protagonists in "Regeneration", has been released from treatment at Craiglockhart Military Hospital where Dr William Rivers (a character pulled from real life) has been evaluating his shell shock. Prior is assigned to a domestic intelligence unit and charged with the task of investigating a female pacifist who has been convicted of plotting to assassinate Prime Minister David Lloyd George. The woman raised Billy like her own child leading her to accuse him of betraying both her and his roots with his investigation. This is a recurring theme in the trilogy as class differences and tensions are never far beneath the surface and Billy's promotion out of the working class ranks of the grunt soldier and into the ranks of officer, usually the bastion of the middle and upper classes, keeps this inter-class tension at the forefront of the book. Away from the front line, Billy now fights the battles within himself; loyal to his fellow soldiers but irrevocably scarred by his experiences alongside them, voraciously seeking sex with women but starting a gay relationship with a retired officer, Billy personifies the author's opinion of the effect of war on the individuals forced to fight in it.
Pat Barker's previous novels mainly deal with the lives of working-class women in the north of England although this theme exists to a slight extent in this novel through imprisoned female terrorist Beattie. However, this novel also encompasses various other themes, including the changing role of women in society, class friction and homosexuality. Because of the importance of psychologist Dr Rivers in this book, Barker also presents a view of post traumatic stress disorder that is both tragic and disturbing. The fact that Dr Rivers was a real-life figure who treated war poets Siegfried Sassoon and Wilfred Owen gives the novel an historical depth which was achieved when Barker drew on her research into Rivers whilst she was a history teacher; as not a lot is known about him as a person she is able to embellish his history without actually re-writing it which would not have been possible had she included a better-documented historical figure. Both Sassoon and Owen were seen as depressed and mentally unstable at the time primarily due to their poetic writings.
Like Regeneration, The Eye in the Door was widely acclaimed and was the recipient of the Guardian Prize for Fiction in 1993. Barker returned to the theme of wartime London in her subsequent novel Art Class.