Leyla and Dak were sure that their parents were dead, but their parents Dagur and Mala were sure their children were kidnapped by dragon hunters. The dragon hunters were mad at the fact that Dagur and his island were no longer hunting dragons (Timeline doesn't really make sense but this takes place after httyd 2 and im ignoring httyd 3 just cause, Also Dak and Leyla don't understand dragons but they can train dragons very well)