Jack Reacher was on a bus and topped a mugging.
It turned out the intended victim was paying back a loan from a loan shark.
The money is to pay the medical bill of their daughter, who lost her medical insurance because her boss didn't pay the insurance coverage of his employee.
It got complicated when the loan shark is part of a gang who was replaced by a competitor.
The mistrust of the gangs lead to more killing. And Reacher is being hunted by the gangs.
It got a bit more interesting when a waitress got involved and sided with Reacher.
It is interesting because it is expected that Reacher would choose a more direct approach. And his confidence has assisted the people to get to the point of safety eventually.
A good story. If you like that kind of direct approach to a problem.