Frosted Flames. The Diary of Payton Wren, #3

Payton and Logan fear they're doomed forever to wander the winding, endless labyrinth leading them to alternate worlds. The prehistoric realm they encounter is filled with unforgiving and unpredictable dangers and also something quite unexpected. hope. They discover a friend and a foe, though, at times, it's hard to differentiate the two. Both hold secrets and perhaps the promise of the way home. Forced to rely on Payton's gifts and Logan's fighting skills, they maneuver through terrible trials and a web of lies.
After a heartbreaking betrayal, the pair must make a leap of faith, which they can only hope will finally see their nightmare come to an end.