This starts out simply enough as another timecop story, with Laumer's always entertaining (and often very funny) hard boiled first person narrative . Somewhere in the middle it shifts gear into a full blown Van Vogt type "recomplicated plot" drama, and you're shot out the end of the novel having read one of the best time travel novels ever written.
Exceedingly entertaining. I can't wait to read again and can't recommend it enough. IMO, it's as good as Harness' The Paradox Men.
And I should add, that there are dinosaurs in the book. So if you're looking for some, while they're not the focus of the book, they do make an appearance in an amusing sequence.

****1/2 -Four and a half stars