This is an excerpt from a short article about Adrian Pasdar:

Co-star Milo Ventimiglia said that his character - Nathan’s all-powerful brother Peter - would be a walking dichotomy in season three. “I think Peter’s going to be exploring many sides to his psyche,” he said. “You’re going to see a side of him that you’re going to love and embrace, and you’re going to see a side of him that you’re going to hate.”