"George Willowfield learned a long time ago that in life everything had to be paid for. You paid in money, or blood, or sweat or time, but you paid.For George, the easiest way was money. So he stole a train and asked the US government for $250,000 to get it back.That's when Frank Angel stepped in - to deliver the ransom and trail the guy who collected it - until he got the money or the guy. The government doesn't like to be held up and Frank was there to see the debt paid - one way or another!"
The author (real name of Frank Nolan) is considered to be one of the foremost authorities on the life and times of Billy the Kid, and the history of the American West in general; he appears frequently in television documentaries dealing with the subject, as well as lecturing to historical societies in the UK and US, and also on cruise ships.
His westerns included the Frank Angel Federal Marshall series of books of which "Duel at Cheyenne" is #2. This series now appears under the pseudonym Daniel Rockfern (which is an anagram of "Frederick Nolan").