Emily Owensby's baby was "defective" and consequently died. Emily takes up running. Her husband argues with her about her new obsession, so Emily escapes to a shack owned by her father on the secluded Vermillion Key off of Florida's coast. Her new neighbor, Jim Pickering, also enjoys the privacy of the key, but the women he brings with him never return home. Emily's curiosity leads her right into the hands of the madman, and soon it's her legs that are her only hope for survival.