Science fiction writers have come up with strange depictions of alien life but nothing to rival a creature with a beak like a parrot, no bones in its body, three hearts, blue blood, skin that can change colors, and arms growing out of its lips. Enter the world of squid and octopus, where cannibalism is practiced daily, mating can involve amputation, trickery is everywhere and size means everything and nothing.

Renowned underwater cameraman Bob Cranston travels to remote places where these alien creatures are most likely to be found, enlisting the help of scientists and experts along the way to locate and identify them. But ultimately, he will seek the most dangerous and least understood of them all, trying to communicate using a never-before-seen or used technique - and he will do it alone.