A mighty task faces Tom Swift in completing his exciting new project--colonization of the moon. To accomplish his historic goal, Tom must first perfect his latest invention, the space solartron, a matter-making machine essential to human survival in the bleak conditions beyond our atmosphere. The challenges are many and daunting, and the young inventor must fight for every step of progress against the danger and mysterious happenings that plague him. A wily foe threatens the family of a lifelong friend, and secret connivers make outrageous claims against Swift Enterprises. Just as success seems assured at last, Tom suffers the most devastating blow of all when his father vanishes into the dark void of space, leading Tom and his pal Bud Barclay on a frantic quest across one hundred million miles to the borders of another world!