The prince disguised himself as a horse-shoer and went to the castle. He put shoes on the horse with four golden shoes, and hearing the bird Grip would not sing, declared that it lacked something and if he could see it, he could learn what it was. He called the bird by name. It began to sing, and caused the princess to smile. The king's sight recovered, and he recognized the horse-shoer as his youngest son. He banished the older sons, but the youngest married the princess and lived happily ever after.