The Dragon Queen

Hiccup Horendous Haddock the Third, and his girlfriend Astrid, have seen a lot together. One thing they haven't seen is a mysterious dragon called, the Avenger. When this mysterious dragon shows up on dragon's edge wounded, and the gang's dragons start acting strangely towards it, will they discover that they aren't the only dragon trainers out there?
Alvin the Treacherous had many warriors, but Savage was the best. So he picked Savage to be his right hand man, the only catch, Savage couldn't have family tying him down. So he sent his wife and young daughter away, hoping they'd be safe without him. He was wrong, his wife was killed by berserkers, and yet his daughter survived. When the Avenger dragon met the orphaned girl, what were they to do but become friends?
So what will the gang do when Savage, now under Dagur's tutelage, leads Dagur's army in an attack on Berk? Will they be able to fight? Or will Dagur and Savage destroy the gang once and for all?