Chapters 15-16, The Black Crochan, and The River Summary

Taran offers up his brooch and the witches accept it in exchange for the cauldron. The companions take iron bars and hammers from the stables and attempt to destroy the cauldron, but all their strikes bounce off it. Orddu sees them and explains that there is only one way to break the cauldron. A living person must climb into it willingly, knowing that they will die if they do so. In order to destroy it, someone must give up their life.

The companions decide to take the cauldron back to Caer Dallben where Gwydion can plan how to destroy it. They tie it to the horses and trudge along with it, skirting around the swamp because they cannot be sure of finding a safe path without the brooch.

That...