What happens when sound is no longer understood merely as something we hear, but as a material force-a trace of colonial violence, ecological devastation, and hidden resistance? In "UNDERPLANET," Xenia Benivolski radically rethinks the relationship between sound, matter, and the Earth. Through three material thresholds-glass, metal, and worms-she unfolds a dense, poetic inquiry that intertwines experimental sound art with decolonial ecology and speculative materialism. From Annea Lockwood's resonant glass works and Suzanne Kite's proposition that computers are nothing more than pulverized stones to the posthumous sounds of Cheb Terro, the book renders audible what pulses beneath the surface of global capitalism. Here, decomposition is understood not as an ending but as a generative force. Rot, stuttering, and scratched vinyl records all carry a subterranean knowledge that resists the logistical order of the dominant world. A book for readers interested in sound studies, art theory, ecology, and decolonial philosophy.