On an unknown day in January, the narrator sits in her living room after tea, smoking a cigarette and reading. She reflects that the lit coals of the fire remind her of a cavalcade of knights and distracts herself from these thoughts by catching sight of a black mark on the wall above her mantlepiece. She wonders if it was left by a nail used by the house’s former tenants to hang a miniature.
From the outset, this story is grounded in a domestic scene from the narrator’s past, which sets an immediate contrast to the direction of her thoughts. Her military associations with the fire reveal her preoccupation with the ongoing war, and this first appearance of the mark demonstrates both her desire for distraction and her attempts to reconstruct the past.
Deciding that the mark was too large to have been left by a nail, the narrator ponders the mystery of life and the inaccuracy of thought. She compiles a list of all of the possessions she has lost in her life, including book-binding tools, bird cages, a hand organ, and jewels. She compares life to a hectic and rapid ride on the Tube, mourning its wastefulness, informality, and haphazard nature.
Her reflections on the mark reveal how difficult it is to understand the full history of something just by observing it. However, human lives are defined by loss—even objects as valuable as jewels disappear. Her reference to the Tube displays a particular ambivalence towards technology and contemporary attempts to control nature and construct efficient industrial lives.
The narrator realizes the mark isn’t a hole and wonders if it is a rose leaf. She compares the dust on the mantlepiece to the dust which buried Troy and considers herself a poor housekeeper. A tree taps on the window outside, and the narrator pictures Shakespeare sitting in an arm-chair before a fire like hers, and wishes for a life without interruption. Her historical fiction about Shakespeare bores her, and she yearns to land on a pleasant train of thought that would reflect well upon herself.
If the mark is a rose-leaf, it signals the intrusion of nature into the home. The narrator’s considerations of her housekeeping allude to dissatisfaction with gender roles, while also confirming the inevitable return of civilization to nature, a sentiment also confirmed by the tree’s interruptions. The narrator tries to anchor herself in Shakespeare, arguably the most potent symbol of the achievements of civilization, but her loss of interest signals the incapacity of even one of the greatest thinkers of mankind to satisfyingly distract one from one’s thoughts.
The narrator dwells on the notion of self-image. One constantly “dresses up” the figure of herself in her mind, and the narrator wonders what might happen were this romanticized internal mirror to disappear. The only reflections left would be in the eyes of strangers on the omnibus, which she thinks future novelists will write about. She also thinks about the generalizations and habits that define one’s life, but change and disappear across generations, which leads her to consider the “illegitimate freedoms” that can come with the passage of time.
The reference to self-image is ironic, as the narrator gives very little detail about her life in this stream of consciousness—however, if this “romanticized image” refers to her thoughts on learned men and civilization, the subsequent image of strangers on the omnibus confirms the alienation and anonymity actually present in that civilization. Her jump to generalizations re-introduces a fascination with the war, although her cynicisms about civilization result in a faint hope. If current habits are just “dressed-up” versions of reality, the passage of time permits changes in that reality and the potential for liberation.
The narrator notices that the mark projects from the wall, which leads her to believe it might be a nail painted over by past tenants but revealed with the passage of time. She thinks about other mounds, such as the barrows on the South Downs which retired Colonels explore in the role of antiquaries, seeking evidence of past generations to determine whether they belonged to camps or tombs.
The belated realization that the mark projects from the wall indicates that things which seem superficial at first may contain hidden depths. However, she connects her desire to identify the mark with the futile attempts of antiquaries to determine the nature of the barrows. In the end, it may be impossible to reconstruct the past, and the narrator leaves readers to wonder what is proved by the fragments we are able to identify.
The narrator decides that nothing would change were she to stand up and identify the mark, as knowledge itself is the uncertain project of “learned men” following in the footsteps of “witches and hermits.” She prefers to picture a world without specialists, where thoughts resemble experience and she could use them to experience the natural world.
The correlations between learned men and witches and hermits cement the narrator’s critical opinion of the male sex while also dismissing the history of human reason as mere superstition. As an antidote to the superficial world of specialists, the narrator arrives at the natural world, which appears to be more solid.
The narrator realizes that her preoccupation with the mark is an act of self-preservation. She cannot take action against Whitaker’s Table of Precedency, but she can put an end to disagreeable thoughts. She wants to find pleasant thoughts and fixates on the solid image of a tree, growing outside the bounds of human knowledge and creating an environment for cows, rivers, and water-beetles. She thinks about a tree’s lifespan through the seasons and its afterlife in human homes and workplaces.
In this crystallizing moment, the narrator realizes that her entire fixation with the mark has its origins in frustrations with larger social problems and structures that she cannot change: the war, and the masculine social order, represented by Whitaker’s Table of Precedency. Instead, she fixates on the symbol of the tree, which stands for the opposite of mankind: a slow pace, growth, and the provision of symbiotic community.
A voice interrupts the narrator’s train of thought and drags her back to the living room. Someone stands over her and says that he wants to purchase a newspaper despite the futility of seeking news during the unending war period. He complains about the snail on the wall, and the narrator realizes that the mark on the wall had been a snail the whole time.
This interruption marks the story’s climax (or anticlimax), simultaneously revealing that the narrator has not been alone and identifying the mark on the wall as a snail. The voice likely belongs to the narrator’s husband, and his presence casts a pall on her reflections about the isolation of the modern era. Her final fixation on the snail conveys the mark’s ultimate purpose, which was to distract her from her unpleasant thoughts about the war and provide hope for an alternative to a destructive civilization.