Episode Title:A Matter of Perspective.Episode Description:Now too aged to fulfilled its duties, the Defenders' Eruptodon passes its mantle of Great Protector to its child and leaves for Vanaheim, the final resting place of dragons that no human has ever seen. The twins disobey Hiccup's orders and follow the Eruptodon to Vanaheim to complete their Viking travel guide, leaving all the Riders stranded on the island and unable to leave thanks to the Sentinel dragons guarding it, which have developed a counter-defense for every dragon. Using Mala's advice to look at things differently, Hiccup learns to use the Sentinel's behavior and abilities to his advantage and with help from the Eruptodon, manage to escape, and Hiccup destroys Tuffnut's guide to ensure that no other human will discover Vanaheim.