A top secret military base in the desolate Welsh mountains is staked out by three young reporters looking for a story on experimental test planes. They unwittingly discover a military and government testing programme involving a creature whose fur has the ability to turn invisible in moonlight. The creature escapes its enclosure during a storm and begins to stalk the dark and misty moors where the trio are camped. They are hunted both by the mysterious invisible creature and the military who will stop at nothing to keep their experiments a secret from the world. Another man on the mountain, a photographer, has managed to photograph the Silverhide and he holds the key to their survival and to the chance of exposing the story to the rest of the world. If only they can survive...