Hiccup discovers that the town's water shortage has been caused by the Outcasts' plan to hide Whispering Death eggs under Berk, which soon hatch and tunnel underthe island, threatening the villagers.
Elenco:
Jay Baruchel
,
America Ferrera
,
Christopher Mintz-Plasse
,
T.J. Miller
,
Zack Pearlman
.