Mr. and Mrs. Garstone
Mr. and Mrs. Garstone are white colonial settlers of Kenya, whose murder in their home by rebellious ‘‘unknown gangsters’’ initiates the events of the story. The news of this murder "was all on the front pages of the daily papers and figured importantly in the Radio Newsreel.’’ Their murder is significant because of its political implications: ‘‘Perhaps this was so because they were the first European settlers to be killed in the increased wave of violence that had spread all over the country. The violence was said to have political motives.’’ The widespread news and "talk'' of their murder and betrayal by their own "houseboy" is significant because it creates an atmosphere in which Mrs. Hill becomes afraid of Njoroge, her own "houseboy.'' It is this suspicion that ultimately leads her to shoot and kill him in what she believes to be an act of self-defense.

Mrs. Hardy
Mrs. Hardy is one of the white settlers who, along with Mrs. Smiles, visits Mrs. Hill to discuss the murder of Mr. and Mrs. Garstone. She is described as "of Boer descent and had early migrated into the country from South Africa. Having no opinions of her own about anything, she mostly found herself agreeing with any views that most approximated those of her husband and her race.’’ Mrs. Hardy represents the closed-minded, ignorant white settler who does not bother to question the racism inherent to the European presence in Africa. Her tendency to adopt the opinions of those around her, and of her "race'' in general, exemplifies the ways in which a racist social and economic system is perpetuated.

Mrs. Hill
Mrs. Hill is a white European settler. As her husband has died and her children are in school in England, she lives alone, without family. Mrs. Hill holds the social status among the white settlers of being one of the first, and most prominent, of the plantation owners in the region: ‘‘Being one of the earliest settlers and owning a lot of land with big tea plantations sprawling right across the country, she was much respected by the others if not liked by all.’’ Mrs. Hill is a liberal, who takes pride in what she considers to be her generous and fair treatment of the African people who work on her plantation. Her ‘‘smug liberalism, her paternalism,’’ however, is resented by Njoroge, her "houseboy.'' The limits of her self-perceived kindness toward Njoroge are tested when she assumes he has come to her house to kill her—and shoots him in what she believes to be her own self-defense. Although the reader knows that Njoroge has in fact come to rescue her from his fellow brethren, who themselves plan to kill her, Mrs. Hill remains ignorant of his true intentions in knocking on her door at night: ‘‘She did not know that she had in fact killed her savior.'' Nonetheless, her fellow white settlers perceive her act of murder as one of bravery and heroism: "On the following day, it was all in the papers. That a single woman could fight a gang fifty strong was bravery unknown. And to think she had killed one too!’’ Mrs. Hill, however, seems to be disturbed by her own conscience in the matter; while her friends are congratulating her on her act of "bravery," "Mrs. Hill kept quiet. The circumstances of Njoroge's death worried her. The more she thought about it, the more of a puzzle it was to her.’’

Njoroge
Njoroge is the man who ultimately becomes the "martyr'' of the story's title. He has worked as Mrs. Hill's "houseboy" for over ten years. He is described as ‘‘a tall, broad-shouldered man nearing middle age.. .He wore green trousers, with a red cloth-band round the waist and a red fez on his head.’’ Njoroge first appears when Mrs. Hill calls him to bring tea. At the end of the day, Njoroge returns to his hut. Although he has two wives and several children, they have been sent to live elsewhere. He resents Mrs. Hill's ‘‘smug liberalism’’ and "paternalism'' toward him. He has planned that night, with other Ihii (Freedom Boys), to kill Mrs. Hill as an act of rebellion against the settlers. However, as he awaits the arrival of his fellow rebels, he begins to think of Mrs. Hill's children; seeing her in the light of her role as mother to a family, Njoroge finds that he cannot bring himself to kill her. He decides instead to run to her house and warn her before the Freedom Boys arrive. Mrs. Hill, however, incorrectly interprets his knock at her door as an attempt to gain entrance and kill her-and she shoots him in what she believes is self defense. Njoroge, as Mrs. Hill's would-be "savior," thus symbolically becomes a "martyr'' in the Christian sense of the word—he becomes a Christ figure who dies for the sins of the white settlers against the African people.

Mrs. Smiles
Mrs. Smiles is a European settler who, along with Mrs. Hardy, discusses the murder of the Garstones with Mrs. Hill at the beginning of the story. Mrs. Smiles is the most aggressively racist of the three women. The opinions she holds of the African population are associated with the ‘‘missionary" attitude most typically held by Europeans in Africa: ‘‘Mrs. Smiles was a lean, middle-aged woman whose tough, determined nose and tight lips reminded one so vividly of a missionary. In a sense she was. Convinced that she and her kind formed an oasis of civilization in a wild country of savage people, she considered it almost her calling to keep on reminding the natives and anyone else in fact, by her gait, talk and general bearing.’’