The Plum series only has a paranormal aspect when Diesel is in the story--and he's just in a few books that are shorter than the regular ones. I enjoyed the early books in the Plum series a lot, the later ones not so much.

@Reflections I heard the series grew to become monotonous as the series went on. When I checked the Diesel books were in between books like 1.5. I'll still have to check out One for the Money and so forth series when I have actually chance though. But for right now I enjoy the Lizzy and Diesel series. Plus I don't have the time to start another series.