This book is a spin-off from the DreamWorks Dragons movies. Readers who have seen the movies will easily identify with the characters: Hiccup, Stoick, Gobber, and Astrid.

A Rumblehorn dragon is attacking the Dragon Riders’ fort nightly. Gobber decides to build a wall to stop the dragon. While back at the village, Stoick is giving everyone a hard time. Hiccup soon realizes Stoick is missing his old dragon. Hiccup and Stoick will help the fort by tracking down the dragon. Stoick is able to lasso the dragon. The dragon flips Stoick up onto its back then flies out to show Stoick the real problem. A giant ocean wave is headed towards them. They head back to the Riders’ Fort and build Gobber’s wall even “longer and stronger to block the wave.” The village is saved and Rumblehorn stays to be Stoick’s new dragon.