Don Pedro, the eldest, goes out in search of the Adarna bird on a horse (yes, it's kinda important... kinda). However, after three months of searching, he fails to find the mountain the bird lives in, the Tabor mountains.
At some point, while he's wandering in a field, he sees a high place and goes there, and his horse dies as soon as he reaches the top (and unfortunately, it's not the mountain either). He takes the supplies that he has with him, and then walks on in search of the said Tabor mountains.
Fortunately, he eventually reaches the mountain and soon finds the tree the Adarna bird resides in. (I mean, how could one not when it's shiny as heck?) He sets up camp there and lies in wait for the bird.
It takes a long while for it to come (like, all the other flocks of birds pass by and everything), and soon Don Pedro decides to just rest there for the night and then leave the next day (maybe just say that the bird didn't come or something). But in the middle of the night, the Adarna bird comes in and does its usual thing of singing and then pooping before going to sleep. And since Don Pedro had slept so soundly due to his tiredness (the song does not help his chances at all, I mean, it's supposed to help his father sleep soundly again, right?), he gets hit by the droppings and turned to stone, leaving the kingdom to wait in vain for his return.
I took a while reading this cause I had to look up some of the words, and man, some of them aren't exactly used currently. I might include a sort of glossary in the future... Maybe I should.
I'm not really sure what to think of this part, to be honest. But man, that horse must have been overworked to have it die on the way...
I do understand how he could have felt, spending all that time with possibly nothing to show for it. But at the same time, I'm getting the feeling that he just went about it rather willy-nilly instead of actually having a plan. But I guess I might learn more about him in the future stanzas. Let's see how it goes.