Quick recap
Exiled from his tribe, Hiccup lives on the run with Toothless and other loyal dragons, disarming traps and freeing slaves. To spy on the enemy, he reaches Prison Darkheart, a slave prison, and finds that prisoners are being forced to search for the Dragon Jewel, the jewel that kills all dragons. Camicazi is freeing people too, and Fishlegs has vanished, dragged under the sand by a dragon's hand. Hiccup has to find his friend and the jewel before they fall into the wrong hands.
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