When traditional radio and cellular networks fail underground, can a chain of old Android devices create a digital lifeline? This episode explores the engineering reality of building an impromptu mesh network using consumer electronics. We dive into the software workarounds like Meshrabiya and NetShare, the physics of Wi-Fi propagation through concrete, and the harsh trade-offs of latency, heat, and battery life. Learn why the "half-bandwidth rule" makes multi-hop networks challenging and how to strategically place devices in stairwells to maximize signal. We also discuss when specialized apps like Briar are more reliable than trying to force a high-speed connection.