The titular forest is the real 'Aokigahara Forest' in Japan, also known as the 'Suicide Forest'. Hundreds of people attempt to take their own lives there every year with bodies difficult to find within its 14 square miles of dense woodland and caves. Yea, dark stuff...
Game of Thrones stalwart Dormier plays twins, Sara and Jess. The former lives in the US in relative bliss with her handsome boyfriend (Irish actor Eoin Macken), the latter moved to Japan years ago after a tragic incident in their childhood. When Sara is informed that Jess has ventured into the Aokigahara Forest and told to fear the worst, she immediately flies to Japan to find her sister; once there she soon befriends a mysterious stranger (Taylor Kinney) who agrees to travel into the woods with her.
There is a perverse gravitation to this kind of material in horror. If there's some semblance of reality, it will scare more - which is obviously the point. Unfortunately, The Forest takes an interesting set-up and demolishes it with a muddled plot and a barrage of twin cliches.
The most frustrating thing about it is that there's quite probably really good film in there somewhere. Helmer Jason Zada has an eye for atmosphere and Dormier is an actress very much on the up, but the script is so lost up its own hole no GPS could help it find its way out.
A couple of jumpy moments aside, this is a wasted opportunity to do something truly chilling.