"The Gospel According to an Executioner," by Russian writers, brothers Arkadiy and Georgiy Vainers. http://www.lib.ru/RUSS_DETEKTIW/WAJNERY/evangelie2.txt
This novel was written at the very end of the 1980's, and a few excerpts from it were published during the Peresroika years in a Soviet literary magazine (I believe it was "Druzhba Narodov"). It struck me back then, but now, when I found the full text of the novel on the Internet, it strikes me even more.
It's an eery, dark, macabre fantasy, where the main hero, Pavel Khvatkin, is a fictional middle-rank officer of the Soviet secret police (back then called MGB, later KGB, now FSB). The story inwinds in the late 1940's and the early 1950's, covering the time when the MGB, with ailing Stalin's approval, started a grandiose scheme aimed at a total annihilation of the Soviet Jewry. This scheme never came to pass in its full version because Stalin died in March 1953. However, its initial stage, the "revealing" by the MGB of the so-called "conspiracy of medical doctors-assassins," did materialize - between 1949 and early 1953, a number of top-ranking Soviet doctors whose names were Jewish (M.S. Vovsi, Ettinger, Shimeliovich, Rosenbaum, brothers Kogan and other) were arrested, tortured, and made "confess" that they deliberately poisoned or otherwise killed top Soviet Communist Party officials, writers, etc. Their "confessions" were widely publicized and were supposed to stir anti-Jewish sentiment among the Soviet people.
In the novel, Khvatkin, a professional killer who is able to murder five stong men in a minute with his bare hands, is shown as an officer assigned to the "doctors-assassins file." However, he is also a total cynic, a man who completely despises the Soviet system and the Communist Party ideology. He does exactly what he is expected to do in order to be promoted up the ranks - participates in searches, arrests, interrogations, plays "mind games" aimed at breaking the will of his Jewish captives; however, while at that, he collects most detailed dossiers on the top MGB generals and also on the Kremlin functionaries who supervise the MGB proceedings. In all this bloody rigmarole, his only true objective is to save the life of a daughter of one of the "doctors-assassins," astonishingly beautiful Rimma Kogan, whom Pavel Khvatkin really loves with all his heart, in spite of all his cynicism, and with whom he conceives a child. Helping his lover and their yet unborn child to survive, Khvatkin cunningly arranges clashes between different forces and groups within the MGB and the Kremlin. At the end of the novel, he participates in the brilliantly designed secret operation aied at removing the then-all-powerful MGB chief, Lavreniy Beria.
The novel contains most detailed and quite shocking portraits of many high-ranking Soviet officials of the late 1940's and the early 1950's (Stalin, Beria, Malenkov, Khrushchev, the Soviet Ministers of State Security Viktor Abakumov and Semyon Ignatiev, the chief of the MGB's Department of Investigations Colonel Mikhail Ryumin, and other). Also, there are some very colorful fictional characters who, at the time when the events take place, are in their 30-s and in whom it is very easy to recognize future members of Brezhnev's top aides.
Great reading, pity it's not been translated into English yet (or so I think).