Danny and the Dragon Ring, Dragon's Tooth Series Book Two

A year had passed since we had escaped from the cave of the Dragon Men, but we were still no closer to unraveling the mystery of the dragon’s Tooth and the world it had come from. It seemed that my father had died in vain. There was only one thing to do: go to Belgium and search for the portal to the wormhole in the forest of the Ardennes. Alfie would join us there. As Kaylee and I made our plans for the summer, little did we know that others had also made plans for us, that we would meet a mysterious Belgium girl named Luna, and that four of us would end up jumping across the universe to a world of dragons and Viking men.