Freeman Dyson, world-renowned astrophysicist, dreams of exploring the heavens and has designed an inexpensive spaceship to take him there. George Dyson, a brilliant dropout, lives in a tree in coastal British Columbia and is designing a giant seagoing canoe. Both men are intensely, passionately dedicated to their visions. Kenneth Brower explores the relationship of this odd father-son duo, whose goals could hardly be more different yet whose approaches are inevitably alike, with insight and sensitivity.