Medvedev's carefully assembled data leave no doubt about the magnitude of the Chernobyl disaster. This is the most comprehensive account of the accident and its consequences, presenting the scientific and technical material in language the layman should be able understand. The record of the Soviet authorities in dealing with Chernobyl was, at best, semi-glasnost mixed with secrecy and evasion, but their recognition of the realities increased as they struggled with the consequences.