Susan Morrow receives a book manuscript from her ex-husband – a man she left 20 years earlier – asking for her opinion of his writing. As she reads, she is drawn into the fictional life of Tony Hastings, a mathematics professor whose family vacation turns violent.
Students on a camping trip discover something sinister is lurking beyond the trees.
Set in the Aokigahara Forest, a real-life place in Japan where people go to end their lives. Against this backdrop, a young American woman comes in search of her twin sister, who has mysteriously disappeared.