Cara and Silverthief (Dragon Storm, Bk. 2)

Cara and her dragon, Silverthief, have always kept each other safe from danger. They're a perfect pair - they don't need anyone else, including other dragonseers. Then they uncover a scary secret. There's something the Guild isn't telling them, and Cara and Silverthief must find out what it is! The risk is too great for them to handle on their own. They need help! But who can they trust?