Every now and then you watch a detective movie hoping it to be something Sherlock Holmes (TV Series) but time and time again you will be disappointed.
A walk among the tombstones tells a story of a retired police, Matt Scudder (Liam Neeson) who is now an unlicensed private eye who got roped into a mystery murder of drug traffickers wife's. Upon initial investigation, it seems like they kidnappers only kidnaps drug traffickers wife's or kids.
The shows has the most creepy atmosphere ever when they reveal the kidnappers with their methods and it invoke the feeling of fear and helplessness for the victims. It also shows that how twisted a person's mind can be and what they are capable of. Come to think of it, sometimes I guess it is not about the money at all. As usual, Liam Neeson alone carries the show perfectly with his cocky method and also his drinking problems.
TL;DR: Liam Neeson catches kidnappers. End of story.