Moonveiled Journeys (Beneath the Dragoneye Moons, #5)

Journey to the Center of Pallos!

Lule is dead. Toke is missing.

Escaping from the devastating battle between the dragon and the Guardians, Elaine and the dwarves have fallen deep into an abandoned, unused mineshaft. Danger lurks around every corner, from starvation, traps, orcs, and more! Elaine must survive in the hostile stone tomb, cut away from the sky, away from her friends and comrades. She needs to find a way to escape, or be buried forever.

Weren't there rumors of the dragon's lair being down here?