"What is the deepest hole which may be dug into the earth?" was first asked about 1947, not 1941, by Enrico Fermi. It can be found in University of Chicago Graduate Problems in Physics, with Solutions, from the University of Chicago Press. The catch is, it appears in the section of experimental problems, for which no solutions are given. To address it, one ought to know something about drilling techniques, materials, and the earth. When Byron Preiss challenged me with the question (he phrased it differently) around the time of the 125th anniversary of Jules Verne's Journey to the Center of the Earth, I knew next to nothing about any of these subjects. Besides spinning a yarn, nothing is more fun than research. The earth's magnetic field begins to collapse, leaving the planet unprotected against deadly cosmic rays and solar flares. Hundreds of thousands of men, women, and children suffer radiation burns and deaths, severe power disruptions, and communications blackouts. If the collapse continues, the ozone layer will be totally destroyed, setting loose plagues of cancer, sterility, mutations, birth defects, and worse. Scientists, rambling to understand these savage new phenomena, ultimately realise that unless an answer is found quickly, all life on earth will be destroyed in a rapidly approaching apocalypse. Against this frighteningly real near-future backdrop, Cyrus and Leiden Hudder-father and son, two of the world's great scientific minds, separated by an undying hatred and resentment-are brought together through the work of fiercely independent physicist Marta McDougal. Marta has developed one of the greatest technological breakthroughs of the age, a machine to bore through the earth's solid crust to reach its very centre... but this invention is a two-edged sword. The ultimate weapon, it could be mankind's salvation-or its destruction! Packed with explosive action in a world poised on the brink of collapse, this high-tech masterpiece is Paul Preuss's finest achievement.