This episode is the first of three parts telling the story of Culhwch, King Arthur's nephew, who is cursed to marry no-one other than Olwen, daughter of the great and terrible giant Ysbaddaden Bencawr. In this part, we hear Culhwch's backstory, his request for assistance from King Arthur, and meet various characters with weird superpowers that are never explained or returned to.

WARNINGS: A lot of weird shit happens in this story. Culhwch's mother goes mad for the duration of the pregnancy, his stepmother is violently abducted and her previous husband killed, Culhwch threatens to shout so loud all the women in Arthur's court go barren or miscarry, the protagonists meet a woman who has had twenty-two sons killed by her brother in law, and the protagonists kill nine dogs that guard the gates of the evil guy's castle. All of these things are mentioned in like, half a sentence, and the story moves on without comment.