"How to Train Your Dragon 2" plot

  Dreamworks announced that last years hit (and Dreamwork's first film that got 98% fresh on the tomatoemeter) How to Train Your Dragon. I never seen it but I hear its really good.
   Anyway Dean DeBlois, writer of the film is in the talks for a Dragon sequel.
More interesting, is that the director said,

There are certain characters and situations that come into play in the second film that will becomes much more crucial to the story by the third. Other threads from the first will begin to pay themselves off in the second. It’s my way of guaranteeing that it is not another adventure that we throw the same five or six characters into, that it feels like part of a larger story.

   I’m going to be starting work on it this year, yeah. Yes I [know things about it]. I know everything about it. I read it last week! It’s phenomenal. And it’s not a sequel; it’s a chapter two. Because there are eight books, so it’s not just finding crazy situations to put our characters in. It’s very much a second act of a three act thing.
  Finally he gave us the plot- The sequel to How to Train Your Dragon continues the adventures of the son of Stoick the Vast and future leader of the Hairy Hooligan Viking tribe. Although the skinny, freckled Hiccup has more brains than the rest of the Hairy Hooligans put together, he has a hard time garnering respect from anyone, least of all his arch-rival, Snotlout. It doesn’t help that Hiccup’s dragon, Toothless, is predisposed to hypochondria and cowardice. During a pirate-training session, them meet up with charming “Alvin the Poor-But-Honest-Farmer,” who is keen to help them discover the legendary treasure of Grimbeard the Ghastly. After a series of hair-raising, humorous escapades on the high seas, a deadly island, and an undersea cavern, Hiccup learns some surprising things about his previously undervalued abilities.
  Not only are they gonna make a sequel but a trilogy. The films gonna come out June 20 2014.