When national park ranger Anna Pigeon needs to find peace, she turns to nature for solace.  Lucky for her, it's close at hand—but then again, so is murder...

Newly assigned to Mesa Verde National Park in Colorado, Anna is enthralled by its ruins: the ancient cliff dwellings of a vanished Native American civilization.  But Anna's reverie is shattered by an inexplicable illness affecting visitors to the popular landmark—and two mysterious tragedies: the death of a child...and the murder of a friend.  Now she must find the very human source of the evil wind that is blowing through the ruins.  For it threatens more innocent lives—including Anna's own...