When the Sadler twins okayed Billy Vivian sending for U S Marshal Shorty Thompson for help, Shorty thought he just needed to meet up with the twins. Together they’d hunt down and find their paint mares, and at the same time catch a couple family killing horse thieves. Now this case was turning into everything but simple. Bank robbers and rustlers are what he ran into. The Double Bar outlaw outfit from Montana was down in Colorado on a horse stealing, cattle rustling spree. They wanted the Sadler’s paint horses.