Finale of the Prydain series and the longest and most dramatic novel of the five. Many deaths in this novel but Alexander continued with the lack of blood and detail.
Taran is traveling home to Caer Dalben after the events of Wanderer when his crow arrives to tell him Eilonwy has returned. He rushes home, eager to propose. Proposal is delayed when Fflewddur arrives with an injured Gwydion. Fflewddur and Gwydion were ambushed by a Arawn who was disguised as Taran and beset by huntsmen. Gwydion enchanted sword [whatever] is stolen.
Gwydion must regain the sword, it's power cannot be used by Arawn. Arawn is also building up for an invasion of Prydain. All of them including Gurgi and Carl, but excluding Dolben, must travel to help. Mag from Castle of Llyr reappears as Arawn's employee who thinks he is a partner. Group is reunited after defeat of Mag. They must all travel to other kingdoms to recruit troops. Fighting happens.
Things happen. Journeys are traveled. Taran travels back to the Free Comots to recruit troops. The Comot men follow Taran because he is Taran. After recruiting through the winter Taran meets up at Gwydion's castle. Another king has turned traitor and allied with Arawn. Fighting happens, castle is taken.
The resulting attack splits the troops. Taran is to follow and harry Arawn's living dead soldiers, the Cauldron-Born. Meanwhile Gwydion will approach Arawn's kingdom from the sea. Much fighting happens. Animals join the fight. Comot character from Wanderer dies. Carl dies. Many more die. Arawn defeated.
Taran is very happy, happy, joy, joy. Gwydion annoucnes all the Sons of Don must now leave Prydain for the Summer Country since Arawn is now defeated. Taran has mixed feelings. Taran announces he will stay in Prydain. All others are leaving and will never return. Eilonwy renounces her inherited powers of enchantment and stays to marry Taran.
1. Much more of an adult novel. The novels have progressed in topic matter as Taran has aged from about 13-years-old until the end of High King when he is about 20.
2. Still no detail about battles and violent death. Little word about blood and screaming.
3. Very chaste romance between Taran and Eilonwy.
4. [Incisive comment comparing the Welsh origins of Prydain versus Lord of the Rings.]
5. I've never read Lord of the Rings.