In Vertical Coffin a sherriff's deputy must deal with attacks on his colleagues in doorways during normal work routines. In The Tin Collectors
Shane's son is kidnapped and he must deal with finding him.
Vertical Coffin has a certain meaning to the law enforcement family. This is a confusing complicated story with way too many initials used, it gets very tiresome in nearly every paragraph and every page the amount of initials used for the different law enforcement departments and it gets too confusing. There are too many characters to keep track of but if you can get it from the first and remember all the characters it will be easier reading.
The Tin Collectors is the beginning of the Scully series and fills in how he ended up with Chooch and how he got together with Alexa, doesn't mean you have to start with this one but it helps to know the background of them. The only thing that I don't like is all the police 'slang' and 'nicknames' and 'initials' used that just makes it confusing and you're not going to remember it anyway, but it is a good series.