An investigative roleplaying game of horrors both ancient and modern, inspired by the works of Arthur Machen and powered by the GUMSHOE system.Britain at the dawn of the 20th century. In the depths of the countryside, cults celebrate ancient rites in hidden clearings and caverns, beasts of legend emerge from their lairs to prey upon the unwary, and powerful beings of folklore and myth stir once more. In the urban sprawl of London and other cities, secret societies struggle for power and dominance, rogue alchemists pursue occult ambitions, and scientists fuse modern technology with ancient mysticism to create new horrors.This is the world of The Terror Beneath, an investigative roleplaying game inspired by the works of the master of horror, Arthur Machen.