Cold Moon (Insolita Luna #3)
M.J. O'Shea

Xan, or X’andrien as he’s known to his people, is furious. His best friend, who also happens to be one of the Fitzgeralds his family has vowed to protect, has gone missing. When they find out where Charlie has gone, Xan has to chase him all the way to Europe and eventually save his stubborn butt in the middle of the night in the freezing cold Romanian forest. He never realized how much his best friend and charge meant to him until he was nearly killed.
Together, they end up stuck in the middle of a political mess that includes the lycans, the werewolves, and some very nosy vampires. If the two of them manage to make it out alive, they may realize that stuck together or not, years of friendship for one stubborn hunter and an equally bullheaded dryad protector can turn into a love neither of them is willing to live without.