L.E. Fitzpatrick 
The Lost Shepherd [EPUB ebook] 

In a world devastated by corruption, Father Darcy has lost his faith. After letting down the very people he pledged to protect, he decides to take a pilgrimage across the dangerous English countryside in an attempt to find his mission again.

There, he meets men hungry for his blood. A vicious, relentless landscape. And two boys more dangerous than anything he has ever seen before. But can he save these children, or will they change his cause forever?

This is a Reacher short story set before the events of The Running Game.