Agatha Christie's clever detective novels may reveal more about the inner workings of the human mind than she intended: according to Dr. Ian Lancashire at the University of Toronto, the Queen of Crime left behind hidden clues to the real-life mysteries of human aging. Dr. Kelvin Lim and Dr. Serguei Pakhomov from the University of Minnesota add to the intrigue with the story of an unexpected find in a convent archive that could someday help pinpoint very early warning signs for Alzheimer's disease and dementia. And Sister Alberta Sheridan, a 94-year-old Nun Study participant, reads an essay she wrote more than 70 years ago.

Paul Auster returns to make the case against destiny, with a chilling tale of a deadly lightning strike.