The Affair

"You want me to impersonate a civilian?" [Reacher said]
"It's not that hard. we're all members of the same species, more our less. You'll figure it out."

Thus begins the sixteenth Jack Reacher novel. Taking place in 1997, he's still an MP, and is being sent undercover into a small town near an army base, while another investigator is being sent into the base it self to investigate a murder possibly tied to base personnel.
His undercover disguise looks pretty much like the post-discharge Jack Reacher we know – no job, good pair of boots, a toothbrush and one shirt. He wanders into town, finds an ally or two and gets to work.
It takes very little time for Reacher to find himself at odds with some locals (I didn't think this storyline was all that satisfying, but it gave Reacher a chance to bash in a few heads). Not that he's ever short of ego, but he seems cockier than I'm used to – I'm assuming that comes from the inherent authority of an MP as opposed to a loan wanderer. Regardless, it was a kick to read his encounters, with this extended family:

He said, “Is there a reason I don't get out of this truck and kick your butt?”
I said, “Two hundred and six reasons.”
He said, “What?”
“That's how many bones you got in your body. I could break them all before you put a glove on me.”
Which got his buddy going. Hist instinct was to stick up for his friend and face down a challenge. He leaned further out his own window and said, “You think?”
I said, “Often all day long. It's a good habit to have.”

that

Killing Floor