Alzheimer's disease strikes at the core of what makes us human: our capacity to think, to love and to remember. The cause of Alzheimer's and whether it can be stopped is one of the greatest medical mysteries of our time. Alzheimer's ravages the minds of over 40 million victims worldwide, stripping them of their memories and often their dignity on a poignant march that can lead to death. Join investigators as they gather clues and attempt to reconstruct the molecular chain of events that ultimately leads to dementia, and follow key researchers in the field who have helped to develop the leading theories of the disease. Along the way, meet individuals from all walks of life who will reveal what it's like to struggle with Alzheimer's. Among them, members of a unique Colombian family who have learned that their genetic predisposition all but guarantees early onset Alzheimer's - but there may be hope. Join these courageous patients participating in clinical trials, and then go behind the scenes of the major drug trials to see how researchers target and test therapies that may slow and even prevent Alzheimer's.