Jeff Greenwood-Adams is the oldest man in England, and for two thirds of his long life has been harbouring an incredible secret. A secret that will one day benefit mankind enormously.
A curious letter addressed to him is then discovered within an alien monolith on a remote and unknown world at the very edge of the solar system. It's a message from his younger brother Alan, whom he hasn't seen for almost a hundred and twenty years. It details the nature of the secret, but not its whereabouts.
Jeff is then compelled to recount a curious legend; one he has dedicated his life to studying. It begins a hundred million years ago with a failed colonisation of Earth, and the unlikely survival of a single alien being who lives up until the twelfth century. He has in his possession an artefact – a symbol of his race, but when he dies passes it onto John, a lowly English medieval serf. John is then faced with an almost impossible quest to take the artefact to a remote and sacred location, then wait an astonishing eight hundred and thirteen years for the rightful owners of the artefact to return for it. The story then fades through the centuries, until an English sailing boat bound for Ceylon strays off course and discovers an incredibly old man living alone on a barren island. He claims to have been there for six hundred years. The soul survivor of that sailing boat then begins a new life in India, but on his deathbed compels his eldest daughter to revisit the island and document the old man's fascinating story. That story then becomes the "Legend of the Last Guardian!'