Dahl uses vivid imagery—descriptive language and sensory details—as a device to illustrate Peter’s journey to piece together the fragmented truth about the hospital. Moreover, throughout the text, concrete details ground Peter in his present reality during moments in which he is in danger of drifting into complete disorientation.

Sensory observations serve as clues to help Peter orient himself. He nearly passes out while piloting his plane, losing track of what he is doing until he sees “the sun shining on the engine cowling of his machine [… and] on the rivets in the metal, and he remembered the airplane and he remembered where he was” (150). The tiny details of the rivets bring him back to clarity. Similarly, the fly crawling across the ceiling of the hospital triggers his memory of the crash: “The sight of this fly, the suddenness of seeing this small black speck on a sea of grey, brushed the surface of his brain, and quickly, in that second, he remembered everything” (153).

Even when the sensory details that Peter observes turn out to contradict the reality presented to him by the hospital staff, their certainty is so overwhelming that Peter pays intense attention to them.