The Cache Keeper (Crystal Cache)

Dylan Fisher continues his geocaching quest to find the next powerful elemental crystal. But he can only do it with the help of a mysterious online ally-Mile High. Tera's safety is still at risk, but he must rely on the secret cache keeper in order to get his hands on the crystal and out of the hands of the enemy-4E Labs. But after another natural disaster, a near fatal car crash, and questions about whom to truly trust, Dylan isn't sure he or any of his friends are safe anymore.