On a summer afternoon in 1998, six-year-old Iris Neff walked away from a barbecue in her small suburban town . . . and vanished.

Missing persons investigator Brenna Spector has a rare neurological disorder that enables her to recall every detail of every day of her life. A blessing and a curse, it began in childhood, when her older sister stepped into a strange car never to be seen again, and it's proven invaluable in her work. But it hasn't helped her solve the mystery that haunts her above all others - and it didn't lead her to little Iris. When a local woman, Carol Wentz, disappears eleven years later, Brenna uncovers bizarre connections between the missing woman, the long-gone little girl . . . and herself.