Peter Williamson is flying a Spitfire aircraft and waiting to land, after having been hit by a cannon-shell and losing most of his right leg. Despite the injury, Peter feels fine, and does not call the blood wagon, preferring to land himself and laugh off his injury with his fellow pilots later. Afterwards, he plans to go to London and cope with losing a leg while there.
As these thoughts run through Peter's head, he starts to feel his vision blur as he begins to pass out. Peter pushes open the hood of his aircraft and realizes that he does not know where he is, but convinces himself he is above the English Channel. He falls out of his aircraft, and keeps his eyes open as he realizes he cannot pass out until he pulls the cord and launches his parachute. As he is falling, he begins to see a surreal interplay of white and black, and he sleeps through the white, which seems to progress slowly, and wakes for the black, which moves quickly. When he wakes up, he is clutching the white sheets of a hospital bed.
Peter analyzes his surroundings, and remembers everything after seeing a small fly creeping along the wall. Then, the nurse walks in and tells him that he is in Brighton after landing in the woods, and he realizes that he has lost a leg. The nurse tells him to sleep, but instead he keeps examining the fly, seeing it buzz around and land in the same spot, until it just becomes a black speck on a sea of gray.
The Army doctor then walks into his room, and tells Peter that his lads were asking to see him, but the doctor insisted they wait a few days. Peter keeps watching the fly on the wall once the doctor leaves, and begins to hear the sound of an airplane in the distance, recognizing it as a Junkers 88. He wonders why there are no sirens or alarm bells, and soon the noise fades into the distance, only for it to start again.
Peter rings the bell and asks the nurse about the sounds of the aeroplanes, but the nurse explains that she did not hear them, and that they are likely ally aircraft coming from France. Peter insists that they were Junkers 88s, but the nurse says that he is imagining things, and asks him to ring the bell if he needs anything else.
That night, Peter again hears the sounds of planes, but cannot discern the type of plane. In the morning, the nurse begins to bathe him, and he tells her that he went to school in Brighton. He remembers the soft water baths he took while in school, when he begins to realize something. That night, he thinks of the hardness of his bath water and the sounds of the Junkers 88s, and begins to doubt whether he is actually hearing these things. His doubt grows, and he begins to fear that something is wrong, leading him to worry and sweat profusely. He realizes that he must get to the window and look out, and he crawls over to the window and pulls back the green curtains.
Outside of the window, he sees a small house with a gray tiled roof on a narrow lane. A small sign is nailed to the hedge in front of the house, and he makes it out to say "Garde au chien" (56). Peter realizes that he is in France, and he crawls back into his bed while in extreme pain, as his amputated leg begins to throb.
In the morning, Peter notices that his nurse is uneasy and restless, and she tells him that someone from the Air Ministry is coming to visit him. He repeats to himself what Johnny, the head of the Intelligence Office, told him: that if he is captured, he should say only his name, rank, and number, and nothing else. The Wing Commander comes in, wearing a normal RAF uniform, and Peter responds to the Commander's question with his name, rank, and number, not sharing anything else.
"Beware of the Dog" places its main protagonist, Peter Williamson, in a surreal and difficult position. This story is ultimately a statement about loyalty in the most difficult situations, as Peter refuses to give information to the enemy forces.
This story begins with Peter refusing to put in a help signal after he has lost his leg and is losing consciousness. As he falls from his plane, a vivid interplay of white and black dances across his vision, as white seems to last a long time, and he learns to sleep during the white periods, while black moves quickly and fades into white. These visions symbolize Peter's uncertain location between his fellow troops and the enemy forces.
After waking from his coma, Peter lies in his hospital bed and sees a fly walking on the "smooth greyness of the ceiling which [is] so clean and grey" (50). Peter's repetitive language seems to mirror the movements of the fly, as the fly buzzes around in circles, always landing in the same spot, "a black speck upon a sea of grey" (51). This fly symbolizes Peter's flight, as he was a black speck flying in the midst of grey clouds. This fly's position on a sea of grey also symbolizes Peter's uncertain state, as it is unclear whether Peter is on Ally or Axis territory; he seems to rest somewhere in the muddled gray between the two.
When Peter is bathed by the nurse, he realizes how hard the water is, and compares this to the soft water he bathed in as a schoolboy in Brighton. Peter's boyhood memories, and the bliss of these memories, is now confronted by the harsh reality of the war. As Peter begins to realize that he is not in Brighton, he also loses boyhood comforts and naiveté.
The green curtains that Peter painfully crawls toward symbolize Peter's last hope, as he tries to ascertain whether he is or is not on enemy grounds. When Peter pulls back the curtains and realizes that he is in occupied France, his body reflects his existential pain, as he faces the reality that he has been captured, and that he must "Beware of the Dog," a symbol for the enemy forces.