The Cradle of Ice by James Rollins
To stop the coming apocalypse, a fellowship was formed. A soldier, a thief, a lost prince, and a young girl bonded by fate and looming disaster. Each step along this path has changed the party, forging deep alliances and greater enmities. All the while, hostile forces have hunted them, fearing what they might unleash. Armies wage war around them. For each step has come with a cost-in blood, in loss, in heartbreak. Now, they must split, traveling into a vast region of ice and to a sprawling capital of the world they've only known in stories. Time is running out and only the truth will save us all.