Akwarium

Aquarium (Russian title Аквариум) is a partly autobiographical description by Viktor Suvorov of the GRU (Soviet military intelligence directorate). The book was initially released on June 1, 1985 by Hamish Hamilton.
The account starts in 1969, when Suvorov, as an ordinary tank company commander, is recruited into intelligence analysis by an up-and-coming Lieutenant Colonel. From there he transfers to Spetsnaz and, from there, into the GRU proper. A combination of circumstances lead to his eventual defection to the British.
The "Aquarium" of the title is the nickname given to GRU headquarters in Moscow by those who work there. "What sort of fish are there swimming there?" asks Suvorov of his boss when he learns about it. "There's only one kind there—piranhas."
Suvorov admits that some details of his career have been altered; for example, he portrays himself as being posted to Austria when, in fact, he was in Switzerland. The reason given is that this allowed him to hide his identity at a time when the Soviet Union still existed and there was the possibility of retaliation against friends and relatives.