"The Mark on the Wall" fits within the genre of psychological drama, wherein the majority of the conflict and suspense derive from a character's internal, introspective journey. Most "arguments" are internal, revolving around the narrator's indecision:
No, no, nothing is proved, nothing is known. And if I were to get up at this very moment and ascertain that the mark on the wall is really - what shall we say? - the head of a gigantic old nail, driven in two hundred years ago, which has now . . . revealed its head above the coat of paint . . . what should I gain? - Knowledge? . . . I must jump up and see for myself what the mark on the wall really is - a nail, a rose-leaf, a crack in the wood?
Note that, over the course of the above excerpt, the narrator changes viewpoints: first, emphasizing that the mark's identity cannot be proven; next, wanting to seek proof to validate her speculation. The narrator is in conflict with herself, attempting to unify her own thoughts and feelings such that she can make a decision about the mark. External persons are rarely referenced by the narrator: the sole exceptions are the use of "we" (i.e. "we had just finished our tea") towards the beginning and end of the story, but these ambiguous "others" do not feature prominently, nor are they the source of any conflict or reckoning for the narrator.
