"Where vice is, vengeance follows."
~Scottish proverb

"Big" Red, an infamous bounty hunter from the Badlands Frontier, receives word about a recent bandit raid on a small town in the northern part of the Badlands which resulted in the death of two ponies related to the Apple family. With the help of his distant relatives - Applejack, Braeburn, and Big Macintosh - he sets off to investigate the murders and bring the hammer down upon the outlaws that were responsible.

All is not as it seems, however, as the Apples soon find out, and they delve deeper into the biggest mystery any of them have ever faced.

What secrets lay waiting behind the guise that is the new Red Steel Railway...?