Alzheimer's is one of the bugbear diseases of aging, a frightening condition that is of great concern to people who are interested in healthy life extension. Unless a cure is found, everyone who lives long enough will eventually suffer its effects. Remarkable progress is being made however, and Nature reports on the latest installment: a much better understanding of the likely cause, and a way to prevent Alzheimer's effects in mice. This is only one of a number of research efforts, resulting from new knowledge and new biomedical technologies. Progress is good!