Faith kept her plain. Science made her complicated. Seventeen year old Lydia Troyer is far from concerned with science or politics. Growing up behind a concrete wall in the exiled community of Hemlock Hollow, life hasn't changed much since her Amish ancestors came to America. She milks her cow by hand, makes fresh bread every morning, and hopes to be courted by a boy she's known since childhood. But when Lydia's father has a stroke and is rushed to the outside world for medical treatment, Lydia poses as an Englisher and leaves Hemlock Hollow. An ordinary light switch thrusts her into a new world where energy is a coveted commodity and revelations about her personal history have life threatening consequences.