This book is hard to classify - what it reminded me of most is the rambling monologue of an older person captured on tape.
The person in question being Ilya Zbarsky, a Russian scientist who for some time assisted in the "eternisation" of Lenin's body. His story is part autobiography, part biography of his father, part historical treatise, part criticism of Stalin and the Soviet system. And it is rambling, not strictly following chronology and sometimes presenting information that cannot be verified as fact.
What I enjoyed most about the book was the insight into the workings of the Soviet state, the paranoia, the submission of science to politics and the weird, macabre outcome of this. In this respect it is a gem.
In other respects it is too personal to be objective (which may or may not have been the author's intention). Zbarsky's attitudes towards his father (a love-hate relationship, yet he only managed to make a living through his father's position as Lenin's embalmer), his time with the Soviet army in Berlin (... showing him in a positive light, but slagging other Russians off), all are reflecting a personal attitude towards history and facts that should be taken with a pinch of salt. It also nearly always shows him as a critic of the regime, yet he seems to have suffered no special hardships for this (he blames his one major personal downfall on anti-semitism, not on politics).
Interesting, sometimes funny and certainly weird - read it as light entertainment (though some parts are too technical for this) or as a subjective and not totally reliable account of life within the USSR under Stalin. By all means, read it. Enjoy it.
Then why not 5 stars?
Just because some parts are annoying in their "me good, others bad" attitude (Zbarsky's love affair in Berlin for instance) and because sometimes the style gets too "realistic" - meaning that for clarity it should have been edited.