Another DB Cooper book that gave a little more insight outside of the perspective given by the investigating officer in Norjak. Filled in some more facts that contradicted some I had read before (whether the dummy chute was left in the plane for example) but these were minor.
Short book, like Norjak and I realize that this is inevitable. The story is perhaps not one to which a great deal more can be added. Authors are going to be stuck with relatively few facts given the success of the hijack and Cooper's apparent lack of any trail that could be followed. Therefore once he left the plane, there is nothing but speculation open to any author - even the discovery of some of the ransom didn't advance the investigation.
Therefore the facts are few, authors on the mystery are left with a guess as to what happened. That's OK but there is no conclusion to books like this so they tend to be short and, ulimately don't really advance one's knowledge except for a few, uncritical facts.