About the book: 1994 / In Isaac Asimov's next story from the series about Azazel, "The Unclear Rumble", his hero George this time asked Azazel for nothing less than ...save the world!. Hannibal West, an amateur speleologist, found a cave containing an unusual stalagmite. If you hit it, the echo sweeps throughout the world at the level of ultrasound. West picked up such a force of impact, the frequency of which kills living human cells…