Who is Nicholas in "The Lumber Room" by Saki?
In "The Lumber Room," Nicholas is the story's protagonist, a boy who is creative and imaginative. He engages in acts of rebellion because he finds life with his aunt tedious and stultifying.
Clearly, Nicholas has a mind that differs greatly from that of his self-styled aunt, who reacts to his creative threat to her authority by arbitrarily rewarding the other children, his two cousins and little brother, with a trip to Jagborough sands. Undaunted by his punishment for having proven her wrong in her authoritative insistence that there is not a frog in his bread-and-milk--he knows because he put the frog there--the observant Nicholas informs his aunt of the reasons that the other children will not enjoy their day at the beach as he remains at home. (Later, Nicholas's predictions prove true.)
During the day, as Nicholas is prohibited from the gooseberry garden, he tricks his aunt into believing that he will try to defy her by sneaking into this garden.
It was clear to his aunt that he was determined to get into the gooseberry garden, "only," as she remarked to herself, "because I have told him he is not to."
Therefore, she spends her time guarding of this spot while he sneaks into the lumber room. There he delights in a tapestry and other works of art and pictures of nature's beauty that appeal to his own creative nature.
Later, Nicholas prevails further in his creative authority over his aunt because she has fallen into an empty rain trough in the forbidden garden and cannot get out. When she calls for help, Nicholas demonstrates his mental superiority as he reminds her that he has been told that he cannot enter this garden and, so, her voice must be that of the Devil tempting him. Thus, Nicholas leaves his aunt stranded, and she must wait hours until a kitchen maid in search of parsley comes to the garden and then rescues her.