The film is set in British East Africa in the early 20th century. Thousands of workers are building the Uganda Railway, Africa's first railroad, and intense heat and sickness make it a formidable task. Two men in charge of the mission are Jack Hayward and Dr. Angus Ross. A pair of man-eating lions are on the loose and completely disrupt the undertaking. Hayward desperately attempts to overcome the situation, but the slaughter continues.