What peril did tree ear encounter on his way to songdo

On the long voyage to Songdo, Tree Ear goes through the bustling town of Puyo. The boy is assaulted by burglars at the Rock of Falling Flowers, and the entireties of the pots are crushed, leaving him with only a single shard to show his lord's aptitude. He proceeds with his voyage, sure that the shard shows that his lord is deserving of the commission.