Slocum's Partner (Slocum Series #258)

Warning: If you cross Slocum’s pal, you’d better not cross Slocum’s path.

After so many years riding solo, John Slocum was glad to be traveling with Harley Duggan. He knew he’d found a man he could trust the moment Harley saved his hide during a barroom brawl. For weeks they’ve been whooping it up from town to town…until they hit Whizbang.
 
This small civic-minded town is keeping a close eye on the two strangers while the marshal’s away. First, they jump to conclusions—mistaking Slocum and Harley for horse thieves. Then they jump the gun—and decide to throw a little necktie party. When an innocent man ends up swinging, the vigilantes realize they have to bury their mistake. Which means they have to kill Slocum.
 
Unless Slocum kills them first...