The Castle of Llyr

Taran escorts Princess Eilonwy to the Isle of Mona for a proper royal education, only to watch her be kidnapped by the enchantress Achren before the first night is out. Lloyd Alexander's third Chronicles of Prydain entry is the series' most romantically toned, with Taran quietly reckoning with his feelings for Eilonwy as he races to rescue her. Eilonwy herself receives exceptional depth for a fantasy heroine of any era, let alone 1966. The Welsh mythological atmosphere is rich without being impenetrable, and the moral framework is clear and virtuous throughout. The honest caveat is that this is genuinely a middle-chapter in a five-book arc — it doesn't work as a standalone — and the middle section sags slightly while the companions gather information. Read in sequence, though, it's a thoroughly rewarding installment in one of American children's literature's finest series.