What if Hiccup had a sister that was like him? Her name is Halla. What if there were two Night Furies?

On the island of Berk, there lies two teens thrown into a war that has been fought for generations. Viking against dragon. When they try to stand out, make their father and village proud, they mess up royally. But when they make a couple of friends out of it, they learn things they never have dreamed of. Of course, it is a forbidden friendship, so they must keep it a secret.