(read in Russian)
"Aquarium" is the title given by officers of the Soviet top-secret military intelligence arm - GRU, to their headquarters. Victor Suvorov is a former Soviet spy who has defected to the west somewhere in the end of the 1970s. This book is one of many he's written to expose the inner-workings of the Soviet military machine.
As far as "spy stories" go, this book is terrific. It has a strong sense of realism around it, and indeed most of the plot is very close to auto-biographic. Moreover, the text is written superbly, in a very absorbing manner - this book is very difficult to put down and stop reading. Suvorov describes his ascend through the ranks of the Soviet military, beginning with a minor tank officer, to being a member of the Soviet intelligence office, going through a special-force (commando) training and finally as an intelligence agent (more commonly known as "spy") serving in Western Europe and gathering information (mostly military secrets) for the Soviet Union. It's a no-bullshit story, certainly far from James Bond-like plots. Serving as a spy is very far from the glamorous job as presented in American movies, on the contrary, it is an extremely daunting profession that puts its employees under inhuman stress for long periods of time.
Suvorov doesn't hide his disdain of the Soviet system, and mentions several times that he envies the life of people in the West. Moreover, he openly scorns people who are ready to sell information to the GRU - why would anyone knowingly serve this awful regime he was a part of ?
Eli Bendersky's website