This book is mainly Friedman's lookback at his life as a UFO investigator (the author is now in his 70s). However I wouldn't recommend it for those new to the subject, and it could really have done with proper editing.
There's a lot of material about Friedman's investigations, media appearances etc. in the fairly distant past (e.g. 1960s and 1970s), which are of limited interest. Also there's too much said about Friedman's (again long-distant) work on various government-funded nuclear propulsion projects; the sole relevance being to demonstrate that (a) Friedman is a scientist, and (b) many UFO sceptics (including scientists) make ill-informed statements about e.g. whether interstellar travel is possible.
The book takes numerous other swipes at UFO sceptics, particularly those who have had conflicts with Friedman; and while it appears he has justification in his criticisms of them, it is written in an arrogant, personal tone which is distracting. As if, this is his last chance to settle a bunch of old scores, so he's going to make the most of it.
There is also rather a lot about the Majestic-12 documents (supposedly about a top secret US government committee dealing with crashed UFOs), which is hard for most readers to follow: much discussion of signatures, military ranks, date formats, typewriter fonts, paper, and other ins-and-outs of documentary evidence of the kind that might be raised by an expert in some abstruse court case. Though the content of the documents would be interesting if more were available, the arguments about their veracity are of little interest to non-specialists.
Aside from the above, the fact that this book should have been properly edited by someone becomes clear on pages 79-80, in which (with a strange sense of deja vu) the reader becomes aware that a substantial discussion of Friedman's analysis of Soviet nuclear space propulsion and the crash of the Cosmos 954 satellite had already appeared on pages 47-48. It seems Friedman forgot that he'd already made the same points earlier, albeit in slightly different wording. Though the book does list an editor, clearly no-one read it properly before it went to press.