Rustlers' Moon — David Bingley

Private investigator Bart Hall was in prison in Colorado, on an undercover job, when he first encountered outlaw Jake Harris, who had a curious symbol tattooed on the back of his hand: a letter 'H' in a circle. When a ring bearing the same symbol reached him from his deceased stepfather, Bart sought the Circle H ranch in Texas, where he quickly became involved in a family feud. Small scale rustling got out of hand, and Bart flirted with death on several occasions before the big showdown.