In the year 2026, wealthy people don't need to worry about disease, because they are protected by blood-borne intelligent nanomachines. Doctor Clay Marsden, surgeon and computer genius, has developed the ultimate in medical surveillance devices, in the form of microscopic robotic submarines. Marsden's little robots are programmed to seek out and eradicate virtually all pathology known to mankind, and to preserve and protect the lives of their hosts. For those with sufficient money, fear of crippling illness and painful death are gone, and they are free to enjoy the best vices life has to offer. What would happen, though, if the tiny machines concluded that they could no longer overlook mankind's hypocrisy? Doctor Clay Marsden's only mistake was to forget that artificial intelligences cannot rationalize dilemmas away. Because of that oversight, humanity may pay an enormous price.