For seven years, Thrumm sat in the Resonant Vaults—a series of hyper-conductive crystal geodes deep beneath the earth. While his fellow Duergar toiled in the rhythmic misery of Laduguer’s lash, Thrumm focused on the silence between the hammer strikes. He discovered that the mountain did not scream; it hummed. This 'Song of the Cosmos' replaced the psychic scars left by the Mind Flayers of his people's history with a profound, vibrating empathy. He realized that the same resonance that holds a mountain together can be used to mend a broken heart or a shattered wheel.
He returned to Duergar society as a 'radical anomaly.' He refused to forge weapons of war, instead using his music to 'conduct' the very atoms of the stone. When the Deep King’s inquisitors came to arrest him for heresy, Thrumm simply turned invisible and walked out, carrying only his stone-framed concertina. He has spent the last decade as a phantom shepherd of the Underdark, following the sounds of distress. He finds the weary, the lost, and the broken, using his ancestral magic not to conquer, but to provide. To Thrumm, a perfectly balanced chair is a fortification against despair, and a warm hearth is the highest form of resistance.