God of Ore (5E)

From publisher blurb: God of Ore is an adventure for 3rd-level characters that takes them from the quiet, mountainside town of Miners’ Refuge into the heart of the Stoneheart Mountains in pursuit of a failed pilgrimage to discover a phony religious relic deep inside legendary Mithral Mountain. The dark, twisting tunnels that bore into the fabled mountain soon reveal that some mysteries are not what they first appear to be.