The Campbells

Susan and Harry Campbell were members of Kenya's Happy Valley Set, who the Steels met at the Hays' Weekend Party.

Harry was a pilot, with his own plane, who was contracted by the investigators to fly reconnaissance flights between Nairobi and the Mountain of the Black Wind. He died when his plane crashed on the last reconnaissance flight, northeast of Mount Kenya. His passenger, Karen, survived.

Meanwhile, Susan accompanied the party on the overland journey. Susan has a romantic interest in Bartholomew, one that he doesn't reciprocate. She was last seen running away across the cavern in the Mountain Of the Black Wind after losing a pranga fight with Pen.