Can a stranger share your memories? That's the question that haunts Brenna Spector when she first sees footage of missing webcam performer Lula Belle. Naked but hidden in shadow, the "performance artist" shares her deepest, darkest secrets with her unseen male audience . . . secrets that, to Brenna, are chillingly familiar. Brenna has perfect memory, able to recall in astonishing detail every moment of every day of her adult life. But her childhood-those...