Jane Lubchenco and Marcia McNutt have reached the limits of science. As the oil surged up, week after week, from the Gulf of Mexico's renegade well two years ago, McNutt, director of the U.S. Geological Survey, and Lubchenco, head of the National Oceanic and Atmospheric Administration, found themselves far removed from the stately pace of their past academic careers. It was the middle of May. The public was restive. The government seemed out of touch. Scientists surveying the Gulf's waters spoke of rivers of oil in the deep. Estimates of the spill's size seemed laggardly inadequate. What was the truth? As two of the government's highest-ranked scientists -- and the first women to lead their agencies -- Lubchenco and McNutt grappled with what science could, and couldn't, do.