The novel, like its two sequels, relies heavily on allusion to, and appropriation of, both historical and literary texts. The "Author's note" for each novel, as critic Allistair M. Duckworth points out, explicitly outline historical texts that Barker relied on when writing that novel. Critic Kaley Joyes describes much of the novel's reading experience as dependent on knowledge of the other texts. Not all the texts represented in the novel are exact copies. Joyes highlights how Barker alters Wilfred Owen's poems so that the reader can witness Owen and Sassoon revise them at Craiglockhart. Joyes argues the subtle use of intertextuality with Owen's works as well as other texts allows Barker to engage politically in a metatextual move similar to those identified by Linda Hutcheon in her A Poetics of Postmodernism — in which Hutcheon describes how fictional texts can question the nature of the historical process, alongside other forms of knowledge, through the means of both explicit and implicit commentary on the construction of that knowledge. According to Joyes, Barker's revisions "destabilize eyewitness privilege and emphasizes narration's accessibility."
The following are some of the most prominent intertextual components in the novel:
- Part of Barker's primary inspiration for the novel are the accounts of the time Sassoon spent at Craiglockhart, as described by Rivers in his book Conflict and Dreams. To give anonymity to Sassoon Rivers refers to him as "Patient B".
- Sassoon refers to Edward Carpenter's writing on sexuality The Intermediate Sex, and it is implied that Sassoon is a homosexual because he states that such works made him feel normal about his sexuality.
- The women in the bar, including Sarah Lumb, are based on characters from a scene in T. S. Eliot's The Wasteland.
- Prior reads one of River's anthropological studies The Todas.
- Owen and Sassoon frequently discuss Craiglockhart's in house-publication The Hydra, which published some of their poems.
- A number of Wilfred Owen's poems are in the text. Owen and Sassoon are shown working on Owen's famous poem "Anthem for Doomed Youth" together. Barker also revises Owen's "The Dead-Beat" as well as using "The Parable of the Old Man and the Young" and "Disabled", but, according to critic Kaley Joyes, she does this "without drawing attention to her intertextual actions." According to Joyes, Barker describes Owen's as often received as an " iconic status as an expressive exemplar of the war's tragic losses". Joyes posits that Barkers' subtle uses of some of Owen's poems may be an attempt for circumventing the "preexisting myth" of about him and his work.
- Literary critic Alistair M. Duckworth describes the novel building on narratives and thematic elements found in both Robert Graves's Goodbye to All That (1929) and Edmund Blunden's Undertones of War (1928).