Lonely Voice

After the nuclear war, there was no life left in the world. Human beings retreated deep underground and built nests to survive. An ethereal voice sounded, who could it be? The mixed sound of electricity made it difficult for me to hear whose voice it was, but it always guided me at critical moments. The silent radio wave has covered the whole world. No one knows where it came from. But I knew I wasn't going to survive. That damn source is gradually approaching this barely surviving underground city, damn it! If dysprosium alloy vacuum tubes are still good... How am I going to survive?