The dragon Riders against the Dark

When Emma is shoved into a portal, she ends up in a land where people ride dragons into battle. But there is a big deadly battle and she's in the crossfire.
She meets their chief, Hiccup.
When the Charmings and Hook find a way to this island, it seems Hook and Hiccup know each other. Although the tension between Hook and Hiccup, there is a greater enemy a foot. He wants to destroy Berk and the new comers. And to what lengths will he go?