Captain and Mrs. Arnold are flying off in their plane, the White Swallow, and apparently have crash-landed in a remote part of Africa. The children, home from school and in the care of Dimmy, team up with Prince Paul, and go flying off in his royal plane to Africa to rescue the Arnolds – and get tangled up with a strange and secretive African tribe with flaming red hair and living within secret tunnels and caves inside a mountain.
