In this vivid study of mimicry and camouflage NOVA shows dramatically how snakes, butterflies, fish, turtles and many other kinds of animals, both predators and their intended victims, use remarkable forms of deception to achieve their goal: to eat, or avoid being eaten.

The TARDIS crew arrives on Earth in the 26th Century in a cave system where a military force is investigating the disappearance of a palaentological expedition.