Dragonborn : 02 : The Twilight Child

Also available in audiobook: 

The second book in the breathtaking Dragonborn series, perfect for fans of Impossible Creatures.

When tragedy strikes the dragon island of Skralla, Alex and her friends must embark on a quest to defeat Drak Midna, before he can reclaim his dragon form and renew his war on humanity.

Their journey takes them to a secret utopia in the magical heart of Scotland, where humans and dragons live together, battling side-by-side against an ancient evil. But that evil is growing stronger every day, the old alliance unravelling as hidden enemies strike from the shadows.

And as Alex struggles to master her own unruly dragon-self, and a fated death draws near, she must seek out the help of the most vicious dragon alive.