Chad: A Frenchman who can see water beneath the Sahara

Out here in the sandy moonscape of eastern Chad, you don't expect to see a diminutive Frenchman marching around, muttering, and staring at his global-positioning device. But Alain Gachet has come here to outdo generations of witch doctors, water diviners, and PhDs. He aims to pinpoint, with scientific certainty, the right places to dig the costly wells that pull precious water from beneath the sand. About 200,000 refugees have fled to Chad from Sudan's violent Darfur region. They each need four gallons of water a day.