At an isolated construction camp in the barren Mexican desert, Reuben, an American doctor, ministers to the sick while simultaneously trying to drown in alcohol the memory of his wife and unborn child who died when he was forced to perform an emergency delivery. One day a troupe of girl "entertainers" led by the worldly-wise Perla pays a visit to the camp. Perla is attracted to the brooding Reuben, but he repulses her advances, preferring to be alone with his bottle of whiskey. Shortly after Perla is left behind accidentally by the troupe, one of the construction workers dies from rabies; and, after Perla has moved on, Reuben discovers that he too has contracted the disease from his pet dog. With only 48 hours to reach a medical center where treatment is available, Reuben's departure is delayed when one of the workers, Pancho, forces him at gunpoint to perform a cesarean delivery on his wife. Once the baby has safely arrived, the grateful Pancho insists upon joining Reuben in his race against time. En route, they pick up Perla and--despite a shortage of fuel, the agonizing breakdown of their jeep, a blinding sandstorm, and a torturous trek under the blistering sun--they eventually reach their destination. Mainly through Perla's persistent encouragement, Reuben has found a new will to live. Perla, however, is less certain of her own future.