Reacher nodded. "If you can't do the time, then don't do the crime." "You got out of the army. So maybe you couldn't do the time either." Reacher smiled. Thanks for the opening, he thought. "I had no choice," he said. "Fact is, they threw me out." "Yeah, why?" "I broke the law, too." "Yeah, how?" "Some scumbag of a colonel was beating up on his wife. Nice young woman. He was a furtive type of a guy, did it all in secret. So I couldn't prove it. But I wasn't about to let him get away with it. That wouldn't have been right. Because I don't like men who hit women. So one night, I caught him on his own. No witnesses. He's in a wheelchair now. Drinks through a straw. Wears a bib, because he drools all the time."
- From Echo Burning (Jack Reacher #5), establishing that Reacher isn't above creative reinterpretation of his past.
Fort Kelham Army Base is located close to Carter Crossing, Mississippi, and is home to the Special Forces involved in clandestine missions in Kosovo. The CID sends two MPs to investigate any possible involvement of the army in the murder and rape of Janice Chapman in Carter Crossing. Major Duncan Munro is sent to Fort Kelham to investigate the base and Major Jack Reacher is sent undercover to Carter Crossing to shadow the sheriff's investigation. In the backdrop of this case are the budget cuts and downsizing the army is undertaking after the end of the Cold War.
The events of Lee Child's The Affair take place in March 1997 six months before the events in Killing Floor (Jack Reacher #1). This is Jack Reacher's final investigation as a military cop and provides him with a reason for leaving the only world he has known. The book takes its name from his relationship with Elizabeth Deveraux - a former marine and county sheriff in Carter Crossing who is actively investigating the same crime. She quickly sees through his cover and they join forces to find the killer.
An investigation cannot sustain itself all on its own. It needs an external source of energy. It needs outrage.
Reacher has to deal with the military's dependence of Washington, the corrupting influence of politicians and the immense pressure to keep the army away from scandal. His supervisors make it clear that they prefer the investigation find a civilian responsible for the rape-murder and this doesn't sit well with Reacher. Further injustices of other murders going unsolved because the victims were black women from marginalized communities adds to his outrage, as does the military's willingness to fabricate evidence to implicate a convenient target. Reacher realizes that the rape-murder is not a one-off but in fact Carter Crossing / Fort Kelham has a serial killer on the loose.
Sgt. Frances Neagley ( from Bad Luck and Trouble - Jack Reacher #11) makes an appearance to give Reacher a warning which is summarily ignored. Reacher also deals with members of a Tennessee militia who arrive in Carter Crossing to destroy evidence of the murders, and Rangers out to arrest him, all of whom are dealt with with typical disdain and violence. Reacher's original travelling accessory (before the ATM card and passport) - his folding toothbrush joins him at this point of his life.