BP is still working to fix the Deepwater Horizon well, which has been leaking since April. The latest effort also hit a glitch when a new cap showed a leak. BP has now said that they have fixed that leak and can move ahead with a test to make sure that they can finally put an end to the gusher. Science reporter for The New York Times, Henry Fountain has been following the story. He explains how the new cap will work and how it will lead to a permanent solution.