It's 1943, and 11-year-old Dewey Kerrigan is en route to New Mexico to live with her mathematician father. The town Soon, she arrives at a town that, officially, doesn't exist. Los Alamos is abuzz with activity, as scientists and mathematicians from all over America and Europe work on the biggest secret of all - the gadget. None of them, least of all Dewey, can know just how much their lives are about to change.