"When wild dragons start flocking to Dragon Island, Hiccup and Toothless are determined to find out why. Hiccup discovers that one by one, the islands the dragons lived on mysteriously disappeared, leaving nothing but ocean in their place! When the Dragon Riders investigate, they find a Screaming Death dragon has grown large enough to consume entire islands. Berk may be next... can Hiccup and Toothless save Berk and find a new home for the wild dragons?"--Amazon.com.