There aren't any reviews on Goodreads, so I'll put something down. This is a very interesting, unique book. It's hard to find, but if you're in a book shop checking out reviews before you buy it, I say go for it. Harvey Barnett, a former head of ASIO, was a good writer, and clearly an extremely intelligent and considerate man. He writes with great clarity and persuasiveness about the role of a security service in Australian society, as well as his views on a number of issues. While he is visionary on most of his takes, some of his scepticism has been proven incorrect, including the role of IGIS and the parliamentary joint committee.
It's obviously dated to the late '80s, and a substantial portion of the book is taken up with the events of the Combs-Ivanov affair and trial, which gets very in the weeds. At the time of writing it would have been extremely interesting but the level of detail weighs down the third quarter of the book.
Recommend to those interested in the history of Australian security intelligence. Don't recommend if you're conspiracy-minded and wish to stay that way.