The Elementals [Kaufman]

Everyone in Vallen knows that ice wolves and scorch dragons are sworn enemies who live deeply separate lives. So when 12-year-old orphan Anders takes one elemental form and his twin sister, Rayna, takes another, he wonders whether they are even related. Still, whether or not they're family, Rayna is Anders's only true friend. She's nothing like the brutal, cruel dragons who claimed her as one of their own and stole her away. 

After the fateful battle between the ice wolves and scorch dragons, Anders and his twin sister, Rayna, have been reunited. But there's no time for celebrating. Anders and his wolf friend Lisabet are hiding away in the mountains of Drekhelm under the watchful eye of the dragon high council. They are perceived as threats, and only the leader of the dragons can keep them safe. Then the temperature in Drekhelm starts to drop throughout Vallen, threatening the lives of the Scorch Dragons. Suddenly, the dragons suspect that the two young wolves are spies for their old pack....

Though Anders and his friends have delayed a war between the ice wolves and scorch dragons, their mission isn't over. With adults on both sides looking for them, they've sought refuge in Cloudhaven, a forbidden stronghold created by the first dragonsmiths. The ancient text covering Cloudhaven's walls could be the key to saving their home - if only the young elementals could decipher it.