Documentary about the Coelacanth, a prehistoric bony fish believed to have been long extinct until one was caught in 1938 off the southern coast of Africa. No trace was found again until May 2000 when a colony of the fish were discovered and filmed.The Coelacanth (Latimeria chalumnae) is an enigmatic and important species of fish. It is the only living member (along with a recently discovered second species of Latimeria) of the lobe-finned fishes, a group believed by some to be the sister-group of the terrestrial vertebrates.Early naturalists, who had studied the fossil records, had long been puzzled and intrigued by this creature, with its lobed, limb-like fins. But it was only with the publication of Darwin's Origin Of the Species, in 1859, and his theory of evolution, that its true significance first became apparent.For here was a fossil species that answered the critics who poured scorn on the very idea that fish could somehow have walked out of the sea and later diversified into the huge variety of land-based animals around us today - including man himself.Yet even after Darwin's theory became widely accepted, no naturalist ever imagined that coelacanths might have survived into the modern age. At least, not until Marjorie Courtenay-Latimer made her astonishing discovery amid the foetid heat of that South African dockside.Marjorie's find turned conventional scientific thinking on its head. But it was by no means the end of the coelacanths mystery. Not by a long chalk. For in the decades after that discovery, the coelacanth continued to defy man's best attempts to study it.