The Green Glass Sea by Ellen Klages
It is 1943, and 11-year-old Dewey Kerrigan is traveling west on a train to live with her scientist father, but no one, not her father nor the military guardians who accompany her, will tell her exactly where he is. When she reaches Los Alamos, New Mexico, she learns why: he’s working on a top secret government program. Over the next few years, Dewey gets to know eminent scientists, starts tinkering with her own mechanical projects, becomes friends with a budding artist who is as much of a misfit as she is and, all the while, has no idea how the Manhattan Project is about to change the world. This book’s fresh prose and fascinating subject are like nothing you’ve read before.