When the Eternal Key hauls Charlie out of his exam room, he knows he's in trouble. Big Trouble. Before Charlie knows it, he is zipped through time to a renaissance castle in Sweden. On a quest to find the truth, he searches for a stolen manuscript, but a demon lurks in the shadows ─ ready to stop Charlie at every turn. Descartes' ideas are Charlie's only chance to triumph, but does he have the mind to survive?Descartes' Demon and the Eternal...