The giant squid in the Harry Potter books is the only one we've ever come anywhere near close to, and nobody has actually seen a real one that wasn't dead, so when the Natural World team set out to try and film a living specimen, they certainly have quite the task on their hands. Cameras allow a team of 50 scientists, engineers and film-makes, exploring the waters around Japan's Ogasawara Islands and deploying underwater robots and state-of-the-art submersible vessels, in the hopes of finding one of the mythical creatures.