a try then watch the movies (SOP for me) however I found out the movies aren't based on the first books but later books in the series.

So I decided to pick up the first book "Killing Floor" to get introduced to the character, series, etc. to see if it's worth going through all of them or even jumping to the books the two movies are based on.

So after about 4 chapters of Killing Floor I'm kinda not that impressed. I'm giving it the benefit of the doubt because it was his first novel and some of the actions/thinking by the police seem to defy some logic (Police not thinking to call the mobile phone number until Jack Reacher suggests it, he being a murder suspect and then the detective deciding to call the number on speaker with Jack Reacher, the murder suspect, sitting right there in front of him listening). But so far it's him getting arrested and 3 chapters of sitting in jail with his thoughts and police interrogation.

So does the book get better? Am I taking the right approach with the novels in going sequentially or is Killing Floor not very good and I should just jump to "One Shot"? What would I miss just jumping to the books the films are based on?