Struggling to recover from the death of their infant daughter, the Conroys -- Martha (Samantha Morton) and Tomas (Steven Mackintosh) -- move to rural Ireland and soon find themselves drawn to one of the town's residents: an autistic orphan named Daisy (Mhairi Anderson). When a string of strange events connected to Daisy starts to occur, however, the couple begins wondering whether she's a victim of superstitions or a dangerous changeling.