The coast of Galicia, Spain, was long-ago considered the end of the known world. Its sea is rough and mysterious, and under its surface there is one of the richest biodiversities of the planet; an ocean full of life and amazing creatures. Cephalopods have settled their kingdom here. They are creatures with a developed intelligence and a notorious capacity for learning and camouflage. With the assistance of Roger T. Hanlon, the most prestigious scientific in the field of cephalopods, this documentary reveals unpublished behaviour of these animals; such as courting, mating and spawning. Sophisticated diving equipment which does not scare the animals have allowed us to show you the Underwater Creatures in a unique habitat.