As the narrator tells the reader in the final sentence of "The Open Window," Vera's speciality is "romance at short notice." As soon as she understands that Mr. Nuttel does not know anything about her family, she jumps on the opportunity to make up a story that will stir up his already frail nerves. While Vera tells the story, it appears to be a tragedy. As the plot unfolds, however, her words turn into a ghost story. One of the elements that makes Vera's story so evocative is her clever employment of imagery to draw Mr Nuttel in.
"Out through that window, three years ago to a day, her husband and her two young brothers went off for their day's shooting. They never came back. In crossing the moor to their favourite snipe-shooting ground they were all three engulfed in a treacherous piece of bog."
She patches together several crucial visual images here. Some are important for the haunting effect they have on Mr. Nuttel and the reader, especially the window that Mrs. Sappleton supposedly keeps open out of her unaccepting grief. As the titular open window is one of the few descriptions Saki provides of the room, this image is already imbued with an ambiguous gravity. When Vera offers context for the central place the window has in the room and the life of Mrs. Sappleton, Mr. Nuttel comes to understand it as half-closed by tragic death. Vera reveals to Mr. Nuttel and the reader that the window is not open for fresh air; instead, it marks the absence of loved ones. When Mrs. Sappleton shows up and keeps looking "past him to the open window," Mr. Nuttel is horrified by the "unfortunate coincidence that he should have paid his visit on this tragic anniversary."
Another significant image is the "treacherous piece of bog" that Vera claims swallowed up the three men. She personifies the bog to add to the miserable mood of the story as well as the mood in the room. As Vera's story continues, she evokes other images that become important not only for their effect on the mood but because they align almost exactly with the narrator's subsequent description of the returning men—whom the frightened Mr. Nuttel believes are ghosts.
"Poor aunt always thinks that they will come back some day, they and the little brown spaniel that was lost with them, and walk in at that window just as they used to do... Poor dear aunt, she has often told me how they went out, her husband with his white waterproof coat over his arm, and Ronnie, her youngest brother, singing, 'Bertie, why do you bound?' as he always did to tease her."
Vera was evidently present when the men left earlier in the day, and had taken note of details like the white raincoat. She has also been present for their return many times before, and could easily predict exactly how it would look and what would be said when they would come back this evening. When the men do actually return, the uncanniness of the images Vera provided heightens the ghostly quality of the story. The combination of the visual imagery in Vera's story and their repetition makes Mr. Nuttel run away. The reader is unable to run away with him and therefore comes to understand the elaborate prank that has just taken place.
