Bounty Hunter
Cornelia Grey

Now, James Campbell is a wanted man. Every bounty hunter in the area is hot on his trail, eager to be the one who finally brings him in. William, though, is determined to get there first. But when he finally catches up to James, he's torn between finding revenge for James' betrayal and helping him escape. Because his feelings for James are as strong as ever, and because he's not convinced that James was entirely wrong...
(Originally part of the Weight of a Gun anthology.)