The eyeball of a fully-grown giant squid is as large as a human’s head. But nobody has ever seen this largest of the invertebrates alive. Zoologist Clyde Roper, too, has only seen a dead specimen, washed ashore. Groping about with his hands, the passionate Roper takes on the identity of his obsession. His dream would be a nightmare to anyone else: sitting in a small glass diving bell and being embraced by sucking tentacles.