"We talk of good luck and bad luck. We even wear, some of us, good luck charms and we tend to select certain lucky numbers if we enter a raffle. No, Norman, you can't tell me that we don't acknowledge the existence of something we call luck." The world, indeed the Universe, is surrounded by intangible energies of which man has, at present, only the vaguest notions. Electricity is such a force. Magnetism, gravitation . . . all once-unsuspected natural forces, now known for the realities they are. And so why not luck? And once the possibility of luck being an actual force is recognised the next step is obvious - a machine to harness its forces. But if one man can attract the good luck, someone, somewhere is due for bad luck. When the machine falls into the wrong hands, the inventors begin to wish they'd stuck to rabbits' feet and black cats . . .