Asteroid A-271 is plummeting towards Earth, and President Eisenhower has made a personal plea for Doctor Tomorrow to itnervene. But Tomorrow smells a set-up. Using his incredible future technology he breaks into the top secret computer databases of the fifties. But here he'll find more than just files and tape-drives. He runs smack into the most dangerous person he will ever meet - a twelve year-old Native American from the future named Mushroom Cloud!