No fundamental obstacle prevents us from developing an effective treatment for Alzheimer's disease. Other troubles of human nature, such as violence, greed and intolerance, have a bewildering variety of daunting causes and uncertainties. But Alzheimer's, at its core, is a problem of cell biology whose solution should be well within our reach. There is a fairly good chance that the scientific community might already have an unrecognized treatment stored away in a laboratory freezer among numerous vials of chemicals. And major insights may now reside, waiting to be noticed, in big databases or registries of clinical records, neuropsychological profiles, brain-imaging studies, biological markers in blood and spinal fluid, genomes, protein analyses, neuron recordings, or animal and cell culture models.