Short version of the review: The book is not a cozy, Bethancourt is immature, and Gibbons just never grabbed me.
A Spider on the Stairs is the fourth book in the series featuring Betthancourt and Gibbons. It begins as Bethancourt is glooming through Christmas at his family's estate and Gibbons is called in to investigate a killing that might be yet another in a series of murders by "the Ashdon killer." He judges the murder to be the work of a different killer and is asked to stay on and help the local police force to investigate it since most of the people who would normally do the work are down with the flu. He calls Bethancourt and the two get down to the business of sorting through clues, trying to identify the victim, and figuring out who had a motive for killing her.
I did not get along well with A Spider on the Stairs. This is not entirely the book's fault. I checked it out of the library because I liked the title and because, on looking the author up, I found an earlier book in the series described as a cozy, and I was in the mood for a cozy. Excerpts of reviews on the back of the book only furthered the impression that I'd be getting something frothy and relaxing.
As it happens A Spider on the Stairs is not a cozy. The serial killer Sergeant Jack Gibbons is ostensibly not investigating casts a very long shadow over the story. I wouldn't put the book quite in the hard-boiled category. There's very little violence actually shown, but even the off-page torture and murder of a series of victims pulls the book out of the cozy category as far as I'm concerned.
Momentum kept me going to just past the halfway mark, at which point I started skimming. The problem is, in addition to the complete absence of coziness, I didn't find either of the detectives particularly appealing. Gibbons has likely been more thoroughly introduced in other books. In this one, he's fairly bland. He watches matters, asks questions, and leaves matters of personality to Bethancourt. Bethancourt is, unfortunately, not terrifically likeable or self-aware. He's a womanizer who has broken up with one girlfriend several times, seems to have had a few others, and is interested in crime for some reason no one, including him, can explain. He does collect gossip for Gibbons, but it hardly seems enough to justify Gibbons hauling him along on cases.
On the plus side: The murder puzzle itself is quite well worked out. While I did not like the constant presence of the serial killer case, I did appreciate the mentions of other, unrelated cases in what was, after all, a fairly large area. The clues were carefully planted and worked out well, leading my post-halfway skim to be a lot more detailed than I had expected it to be--to be honest, I had planned on skipping to the end and calling it a day, in which case, there probably wouldn't be a review here, not even with disclaimers. The inevitable connection between the two primary, apparently unrelated(1), cases was well-thought and not one I would have foreseen. Some of the minor characters stand out well. I was particularly impressed with the sense I got of the murder-victim's personality, the feeling that, yes, she would have been a fun person to know.
I do wonder if this is Chan's usual style and subject matter. Bethancourt spends much of the book being glad he's not working on the serial-killer case because the serial-killer's mind doesn't interest him, and Gibbons, too, is happy to leave that case to Brumby, the detective who specializes in the killers. In fact, the ultimate interrogation and arrest of the serial killer is handed over to Brumby with Gibbons watching admiringly--almost fannishly--as Brumby does his work. Is Chan wanting another, darker, Brumby series? Or is this tone and content typical of her? The review excerpts I mentioned earlier all reference previous work and sound even less applicable than usual to the book I read. I think, however, I'm that I am likely through with Chan. A Spider on the Stairs has its virtues, but it is not my style.
(1) I hope I'm not spoiling things too badly here, but I don't think so. It would be very odd for a murder mystery to have two prominent cases that were entirely unconnected in the end.