'1st to Die' launches the series. I have to admit, I tried it after seeing the short-lived TV show and wanted more. The book is, unsurprisingly, much richer. The internal thoughts of the characters, especially Lindsay's fears and doubts, add a layer the show couldn't quite capture. The source material has a grittier, more procedural feel. If you liked the concept of the show but wanted more depth, the first book is definitely where you should start.