Working from the intriguing hypothesis that Alzheimer"s dementia is the result of a renegade protein-beta amyloid-Tanzi and others set out to find the gene responsible for its production. Decoding Darkness takes us deep into the minds and far-flung labs of many a prominent researcher, offering an intimate view of the high stakes of molecular genetics, the revolution that propels it, the obstacles that threaten to derail it, and the families whose lives are so dependent upon it. Tanzi and Parson ultimately reveal that Alzheimer"s, like heart disease, may be effectively treated-even prevented.