Curse of Arastold — Jo Whittemore

Megan and Ainsley are ready to say goodbye to the magic-infused land of Arylon and journey back to Earth, but their trip is postponed when Ainsley comes down with a serious illness linked to cursed dragon's blood. Hoping for a cure, his friends take him to Raklund where he receives special care from Lady Maudred, who has experience with the magical disease. But her potion fails to cure him and Ainsley is running out of precious time. As he slowly descends into madness, his body is undergoing a hideous metamorphosis. The only hope for a cure lies with Arastold-an ancient and powerful dragon who's imprisoned in a mountain cave. Can Megan convince Arastold, who originated the foul infection, to lift the treacherous curse that is transforming Ainsley into a deadly dragon?