While on a train ride across the galaxy, Compton and Bayta get involved in a murder investigation that is more than it seems.

Finally, here’s a Quadrail story that I enjoyed thoroughly. It has the feel of a standalone book set in the same universe, until the end, when the connection is made. Frank takes on the role of murder investigator, and I love the way he knows so much about all those different species to make determinations about who might or might not be guilty. The book is full of suspicious characters, which makes the reader guess that the murderer could literally be anybody. I had my suspicions early on, and was proven right, but for completely the wrong reasons –but the author did a great job so that I was doubting myself throughout. My one big problem was the sheer number of characters, where I had trouble remembering who belonged to which species, or when Frank had spoken to them and about what. But that’s a minor complaint in a story where Frank didn’t make any deals with the Modhri that he fully expected to break. It was refreshing. The ending was haunting in a way that I didn’t expect, and raises the stakes for the last book in the series.

All of the previous books in this series left me a bit cold. The writing is always good, but I was never a fan of the noir style, nor the way Frank manipulated the Modhri so easily over and over, while it continued to fall for his deceit –even after saying it wouldn’t.

But in this book, the Modhri doesn’t appear until about the halfway point, and begs to make a deal with Frank, because his walkers are being killed off. It’s a good red herring in a book full of them, because by this point, the murderer could be anybody, and the motivation isn’t clear. I thought maybe Kennrick wanted to discredit the Spiders, which would create chaos, allowing the Modhri to take over. But when Modhri finally appears, it’s clear that he doesn’t want chaos, because he plans to use the Quadrail to conquer the galaxy.

It turns out that there were several plots on the Quadrail train, much like in Murder on the Orient Express, except that they weren’t all directed at one person.

Frank and Bayta are heading to the end of the Quadrail line, a station in Filiaelian space that takes six weeks by train. I can’t imagine the people sitting in third class, with their small chairs and no elbow room for that long! Thankfully there are gaming cars and dining cars, and lots of movies. Every time Frank and Bayta need to go to third class, he grumbles that it’s more than ten cars down from where they are staying.

Being employed by the Spiders, Frank and Bayta are awakened by them when one of the passengers becomes very sick and then dies. This never happens on the Quadrail, so Frank starts to investigate. When a second one dies, and then a third, he sees a pattern, that Kennrick’s team from Earth being targeted. The most obvious person to be the murderer is Kennrick himself, but he seems to have no motive. The Shorshians and Filiaelians who die were in favor of the deal his company was trying to broker in genetic engineering, something the Fillies have been experts at for hundreds of years. The motivation is muddied when one who was opposed to the deal is killed. Frank is very thorough, going into all the details, from smallest to largest. He eliminates food contamination, poison at the dinner table, by the air vents, and even by injection when he examines the bodies and finds needle marks –which have been faked.

Complicating the investigation is Filly hierarchy, which doesn’t allow lesser people to go against the wishes of higher ranked society. It seems that Shorshians are similar, but grouped in families. Even the undercover cop has to bow out of what he’s doing when another Filly tells him to stop, even though it directly affects the case.

The author skillfully leads us down one plausible path and then another, only to watch them all peter out. The Shorshians all died from heavy metal poisoning, but there was no way to get it into their systems except through injection, which Frank rules out, even after the doctor’s hypodermic needle is stolen in an elaborate setup. The two doctors, one human and the other Filly, are both accused at one point, especially when they defend the young human Terese German. She was probably the most fun character, as she was sarcastic and annoyed throughout. She just happened to be sitting beside the first Shorshian to be murdered, so Frank keeps coming back to her.

She is a good red herring, as she’s sick often, and they wonder if she has the same sickness the first victim had, especially when both Frank and Bayta start feeling ill. After checking the air filters, Frank discovers that an aerosol was used to kill stomach bacteria, which would allow humans and other species to help clear their systems of heavy metals. As the Shorshians and Filly were killed by heavy metal poisoning, their bacteria must have been lacking, and was more susceptible to the aerosol.

It turns out that Terese is pregnant, victim of a rape on Earth, and is being transported to Filly space for genetic study by Dr. Aronobal and the undercover cop, and was not sick due to heavy metal poisoning.

The Modhri reveals himself at this point, concerned that he only has three walkers left, and that this segment will die if Frank doesn’t find the murderer. Frank enters into yet another agreement with Modhri, but this time it’s to help them both, as it can watch the train in three different locations at once. Frank wonders, as does the reader, if somebody was targeting the Modhri, which brings up the separate hive mind from the previous book.

Eventually, all of the evidence points to Kennrick, but not to discredit the Spiders. He was working to take over the Quadrail by testing various ways to kill people on board and bring weapons past their security for his employer -the same trillionaire who Frank was working for at the beginning of Night Train to Rigel. He reveals that he’s guilty, and then puts a garrotte around Bayta’s neck. As if the story wasn’t complicated enough, once he's solved the murder and the motivation, Frank has to find a way to rescue Bayta without getting her killed. I liked the way she took an active role, though, activating the kwi weapon through telepathy so Kennrick would think it was always active, so it would fail him when he needed it most.

With help from the new class of Defender Spiders, and a convoluted plan to distract Kennrick, breaking many of the Quadrail rules, Frank ends up shooting Kennrick with his pistol, allowing the Spiders to enter his room from the ceiling and cutting all the wires that were strung around as distractions, one of which could cut her head off.

After all that excitement, we still aren’t done, as one of the Fillies has had genetic enhancements that could control the Modhri, which he sets on Frank and Bayta to kill them. It’s only through sheer ingenuity and help from the Defender Spider that he gets away. They break into Kennrick’s luggage safe box, which includes reports on the Filly genetic engineering. Frank reads them with growing horror as he realizes that the Filiaelians are descended from the old enemy that once ruled the galaxy with terror, and which created the Modhri. Their genetically engineered sect was completely destroyed, but the current Fillies are trying to restore that lineage, and one of them has succeeded. Somehow, Terese’s fetus is part of the plan to perfect it.

I liked the confined space that took up the vast majority of the book. Despite the limited setting, the author managed to make the characters and different elements of alien society very interesting. Frank became frustrated by it, and went out of his way to make sure he respected their customs, at least until he was alone with the bodies. The red herrings were numerous and all had plausible motives or opportunity. The mystery was well made, and I look forward to the conclusion, wondering all the while how the author is going to end this in a single book without destroying the Quadrail and/or the coreline. We’ll see.