The High King is the last book in the Chronicles of Prydain by Lloyd Alexander. I’ve also ordered The Foundling and other tales of Prydain; a book of short stories that complements the series.
Even though Arawn Death-lord of Annuvin has suffered great defeats, this time the entirety of Prydain will feel his wrath. The Sons of Don must come together and put aside their quarrels to unite against the forces of Annuvin. Taran and his companions too will join the fray, but do they have any hope of winning free of Arawn and his foul grasp on Prydain?