V.M. Sang 
Wolf Moon [EPUB ebook] 

The group called Wolf have been enlisted into the Erian Army against their will, and they soon learn that an invasion is planned into their homeland of Grosmer.
As the heroes make their escape, they accidentally stumble upon an old Dwarven city, and become friends with them.
Facing enemies on all sides, the five must find where their loyalties lie, and save their homeland from certain destruction.