Deep beneath the earth, something ancient is waking. For centuries the dungeons scattered across the continent were believed to be isolated mysteries-dangerous labyrinths filled with creatures, relics, and forgotten magic. But as new floors open and strange tremors ripple through the world, one truth becomes impossible to ignore: the dungeons are connected. At the center of it all lies the Heartstone, a vast and ancient power buried deep within the bones of the world. When a young crawler named Callum Ashford survives an impossible encounter with that power, he unknowingly forms a bond with something that has slept for millennia. Now the Heartstone remembers him-and its awakening has begun. As cities rise around the growing dungeon at Millhaven and powerful factions move to claim control, Cal and his companions must push deeper than any crawler has ever gone. But the deeper they descend, the clearer it becomes that the dungeon was never meant to be explored¿ it was meant to be protected.

Ancient guardians are stirring. Forgotten civilizations whisper through crystal and stone. And somewhere in the darkness, forces older than history are watching. Because the Heartstone is not just waking. It is choosing. And the fate of the world may rest in the hands of the one person who never meant to touch its power.