Having read "Fate is the Hunter" and loved it I wanted to know more about the author. "Fate" is a string of unconnected aviation vignettes all of which are fascinating, but without any overall context. You don't know whether some incidents happened before WW2, during, or after, etc. Unfortunately, "Hostage" suffers somewhat from the same problem. Gann follows various threads of his own life, sometimes back-tracking in time to start a new one. This can be awkward.
The second problem is the book is overlong. His early childhood is told in way-too-much detail. It's all interesting and well-written, but I found myself slogging ahead at times waiting for him to grow up.
It turns out that aviation formed only a small part of his life, so aviation enthusiasts beware. In fact I recognized several incidents he flits over in "Hostage" that had whole chapters in "Fate". Mostly Gann seems to have been an amateur fisherman, sailor, anything to escape from his wife and kids.
What I found as a revelation is how many books, screenplays and movies this guy wrote. WOW. In his later years he was cranking out best-sellers like clockwork, although some of the movies seem to be tied up in John Wayne's estate and aren't viewable any more ("The High and The Mighty", "Islands in the Sky"). "Soldier of Fortune" is a staple on TV, and "Fate is the Hunter" with Glenn Ford shows up sometimes too (not nearly as good as the book). "Twilight of the Gods" is on often too.
Overall, if you have no special expectations and plenty of time this is a good book to read. If you were hoping for an inspiring life story or lots of aviation stories, you'll be disappointed.