Peder Doterson is totally boy-next-door material. He's cute, funny, and has been around for as long as Miri can remember. He and Miri hang out all the time and get along great—he even calls Miri his best friend—but as Miri and Peder get older, their relationship starts to get a little complicated:
Peder. Normally she would shout hello, but over the past year a strange feeling had come inching into Miri, and now she was more likely to hide from him than flick pebbles at his backside. (1.48)
Miri and Peder no longer have the same ease that they used to. Maybe it's because Peder keeps getting frustrated whenever Miri talks about the prince like she might marry him or something, or maybe it's just because they're growing apart. But they have to work on reestablishing their relationship, or else risk losing it forever.
Despite the fact that he and Miri have a sometimes-rocky relationship (so many misunderstandings about the stupid prince), Peder is still always there for her, no matter what. When she talks about how she's learned quarry-speech, he sits there and listens to her patiently, congratulating her on her success, and when she calls to him using quarry-speech to come help the girls at the academy, he doesn't hesitate:
Peder had brought the villagers, and they were carrying weapons. (22.6)
When the time comes, Peder is there to help Miri. He understands her perfectly, which is why he's the person she chooses to communicate with when the bandits come. He's also the person she reaches out to via quarry-speech when Dan is holding her—Peder recognizes immediately that she needs him to inch the bandit toward the cliff. He just totally gets her like that.