The first 75 pages take some absorbing as there's a lot to take on board about Soviet Administration and applied nuclear physics. But it's absolutely worth it. The following chapters are riveting and often eye-poppung ('a temperature of 1200 degrees Celsius' was something when the roentgens were baffling me). For me the last section was disappointing, although how the disaster led to the breakup of the Soviet Union is very important. But the very end was devastating because of the terrible lack of lessons learned in a global sense.