With nowhere in particular to be Jack Reacher steps off the Greyhound bus at Margrave, Georgia because big brother Joe told him that's where blues musician Blind Blake died. Reacher decides to check out the town on a whim. Almost immediately upon reaching (but after a decent breakfast) he is arrested for the murder. Someone's head was shot off and Sheriff Morrison alleges he saw Reacher leave the crime scene. Reacher knows he hasn't killed anyone, not in Margave anyways but lands up in prison.
Another co-accused in the murder joins him in the cell and Reacher tangles with members of the Aryan Brotherhood. Suspecting the involvement of the police in setting him up Reacher gets himself involved in the investigation after he is released from prison. But a more personal connection is established when he finds out that the murder victim is his brother Joe who was carrying out his own investigation in Margrave. Joe Reacher was looking into a possible counterfeiting operation run by Margrave's Kilner family, who carried on under the protection of the sheriff, mayor and dirty cops. Bodies pile up, including the sheriff himself. Reacher realizes he's arrived at Margrave during a logistical glitch in an otherwise smooth counterfeiting operation. The operation involved collecting hundreds of thousands of $1 bills, bleaching the notes and forging $100 bills on the original (and therefore undetectable) paper.
Reacher and his trusted allies in the Margave police begin to fight back to complete Joe's mission. They send soft targets into protective custody, set ambushes for their adversaries and begin to take down the Kilner family and their operation.
Killing Floor is Lee Child's debut novel introducing Jack Reacher. Reacher is a towering veteran of 13 years from the Military Police. At 36 he's made redundant after the Cold War. During his career he's been posted to bases all over the world and now he returns to the country he's served but never known. Jack Reacher roams the continental USA. He makes no plans or commitments, has no ties, or baggage save a folding toothbrush and an ATM card. After 9/11 he has no choice but to also carry a passport. Like Conan the Barbarian, Reacher is an itinerant brawling giant. He's squeaky clean with no substance abuse issues except caffeine.
He usually keeps to himself except for the annual adventure he stumbles into. He's adept at dealing with most situations after a career policing soldiers, knowledge of weaponry, and an understanding of how violence works. Quick thinking and dirty fighting. He is the mysterious stranger who comes into town on the bus, cracks heads, beds women and solves a problem on his way out.