Whilst on vacation in Thailand with his family, American cop Jake (William Moseley) accidentally interrupts a dark ritual by a mass murderer (Michele Morrone) and is thrust into a supernatural realm. When demons escape, possessing people on the streets, the city is thrown into chaos. To save his trapped family, Jake must ally himself with a mysterious Novice Monk and embark on a journey to discover the source of evil and shut the Gates of Hell.