From the comments I've been getting, quite a few of you have read this book so I'll keep it brief.
Murder Past Due follows library archivist/amateur sleuth Charlie Harris and his trusty sidekick Diesel as they try to solve the mystery of the murdered mystery writer. Trouble is, Godfrey Priest is disliked by the majority of people in town and the suspect list just seems to keep growing. Can he solve the crime before his young boarder, Justin, is wrongfully arrested? Will Diesel ever get the head pats he so desperately wants?!!!
Silliness aside, I really liked this one. It's probably the most solid cozy mystery I've read. The plot was focused and there were a lot of clues leading throughout the story. It was a lot of fun to read and see what surprising twist lay ahead. The who-done-it made sense and didn't feel cheap at all. Overall this is just a really nice, really solid mystery.
Diesel is, of course, my favorite character. In my opinion he's the best character in the book. I don't know if that's a good thing or not. On the one hand, should a cat really be outshining all the other characters? On the other hand, is it possible for a cat NOT to outshine everyone else?
My biggest critique is sometimes the dialogue, specifically the character's speech patterns, drove me nuts sometimes. For example, the way Justin called his mom "Mama" every time. Just felt weird for an eighteen year old to do. I speed read through Peter's scenes because I just couldn't stand the way he talked. I give James credit for really giving her characters unique voices, I just wish she made it more realistic because it did get very obnoxious.
Final rating: 4.5 out of 5 stars, amended from the 4 stars earlier. It's a great book, little cheesy, but it has a cat and is just really cute.