William Twining has it all - a sharp intelligence, dashing good looks, and a noble station in life. There's only one problem: he's broke. With no way to finance his prestigious education, William decides to search through his uncle's mansion for something of value to sell. But William's logical worldview is about to take a hit, when he comes across a mystical seal which he unintentionally uses to summon a demon. The demon's name is Dantalion, a Grand Duke of Hell, who informs the young nobleman ...