Terry Time is a curious and imaginative child with a penchant for transforming reality into fantastic worlds using numbers and his imagination. One day, in the office of his father, a university professor of paleontology, he finds an old telephone capable of time travel. Thus begins the search for the last dinosaur on earth, not in the Mesozoic Era but in 999 AD, the Middle Ages.
In this time unknown to him, he meets two children, Sole and Scoglio, and with them he sets out in search of the legendary Silver Dragon, the creature that – according to legend – will free them from the oppression of the new and stern local lord.
Will the children be able to find the Silver Dragon? And what connection does it have to the last dinosaur Terry has been searching for?