One of them, Kirk Sorensen, left his engineering job to study nuclear physics and start a company devoted to building small, modular liquid fluoride thorium reactors. The goal now may be to build some for the military, a tactic that would circumvent many of the challenges of building commercial reactors in the U.S. We met Kirk at the Thorium Energy Alliance summit in Washington, as well as an Army colonel focused on energy, and the head of the alliance, the thorium advocate and industrial engineer John Kutsch. We also interviewed Alexis Madrigal, senior editor at the Atlantic and author of Powering the Dream, a history of green technology evangelism, David Biello, associate editor at Scientific American, and Phillip Musegaas, the director of Riverkeeper's Hudson River Program, which keeps careful tabs on the Indian Point Power Station, one of the country's many aging nuclear plants located about 30 miles from New York City. The nuclear physicist Alvin Weinberg, who led the first thorium reactor experiment, makes a cameo as well.