When her grandfather injures himself in a fall, teenaged Mary joins her mother in comforting the old man as he recovers. But almost from the moment she walks in the door of her grandfather's home, Mary finds herself drawn into the vortex of her family's hidden past. A mysterious family portrait may unlock the truth but the real action begins when Mary discovers Grandad's old dog whistle and its sound sweeps her into the past where she becomes a witness to dark family secrets. Does she dare tell her family what she discovers?