A remarkable 200-million-year-old fossil - the bones of an ichthyosaur, a giant sea dragon - has been discovered on the Jurassic coast of Britain. David Attenborough joins the hunt to bring this ancient creature's story to life. Using state-of-the-art imaging technology and CGI, the team reconstruct the skeleton and create the most detailed animation of an ichthyosaur ever made. Along the way, the team stumble into a 200-million-year-old murder mystery - and only painstaking forensic investigation can unravel the story of this extraordinary creature's fate.