Gruff Garrett - The Old Lawdog - The Old Nemesis. Gruff Garrett Series, #3

Gruff Garrett, the old and aging US Marshal has one last job to do. It's a routine task that was tailor made to fit his advancing age. Garrett was tasked with going to the small mining town of Blue Rock, and picking up a captured outlaw by the name of John Bryan. At first glance, it seems like a routine enough assignment, a fitting sendoff for an aging US marshal like himself. It shouldn't be so hard for an old timer like Garrett to do, and it seems like the perfect assignment for Garrett to go out on a positive note.
All this changes, however, when Garrett realizes that John Bryan is really his old rival Paolo Dixon, a sly aging outlaw that has a rough history with Garrett. The two old nemeses meet, and tensions run high. Garrett has to escort his old nemesis back to the marshals where he can stand trial for his crimes, but it won't be that simple. Dixon keeps ranting that his gang the 'Poison Club' is out to rescue him and will stop at nothing and kill anyone who tries to stand in their way.
Aside from them, there are other men that Dixon has made enemies with who are also out to get him. Garrett will have to decide whether it's still worth it to finish his job and protect his old nemesis.  How far is the old lawdog willing to go, just to uphold the law?