Sunspire Mountains where to find the missing piece of the puzzle

All around him, bodies writhed, blood spilled, and voices cried out in pain and triumph. Aventus could not pick out any wolf from the others in the throng. He didn't realize that one of Nyra's own had turned on her and no longer could even tell his father or sister from the others. His focus narrowed onto Nyra so that all he saw was white fur and blood blooming into it, and felt her death was assured.

When Nyra tore away, Aventus snarled and pursued, hot on her heels with every bound of his wiry young body. Not so fast, his clashing teeth said. He would not let her get away that easily, and would remain on her trail, tearing at her wherever he could, until well after his energy reserves should have run out, fuelled entirely by hate and a burning need for vengeance.

Even then, he would continue to follow from afar and seek her wherever she might run. Nyra did not deserve a clean break from Ursus after what she had done to his beloved mother, and so long as he drew breath, he would not let her have it.