The big engine that really could

kw: book reviews, science fiction, space fiction, mysteries

If Agatha Christie had tried her hand at science fiction, this is the kind of story she would write. Here's the scene: aboard a train that takes a few weeks to cross…the Galaxy; something like eight nonhuman species, plus humans, are aboard; two weeks into the trip two nonhumans die; Frank Compton, former space cop, and his associate, the half-human Bayta, investigate; the murderer, it turns out, is very, very clever and very, very elusive; more deaths occur – they seem to be dropping like dominoes; there is no getting off this train short of its destination, still a month away.

In the world—or Galaxy—created by Timothy Zahn for The Domino Pattern, latest in his Quadrail series, mysterious aliens have produced a galaxy-spanning "subway tube" with trains energized by a "coreline" that zips them along at about a light year per minute. The "local", with stops every few dozen light years, follows the spiral arms, and even an "express" that makes few stops takes about 100 days to sweep inward then outward a total of some 150,000 light years. So there is a "super-express" that cuts straight across, runs a little faster, and gets you there in 40 days, nonstop.

Upon this backdrop the mysterious series of murders, and their investigation, play out. At the risk of spoiling one of the plot twists, an innovative murder method requires disseminating (in food) microbes of the heavy-metal-concentrating type, which are already loaded with the toxic metal Cadmium. At a later time, a potent antibiotic is sprayed into the air supply. The dying microbes release their Cadmium and the victims die of heavy metal poisoning. This requires beings who are very sensitive to Cd poisoning, which the author conveniently supplies.

Humans take a bit more killing than that. According to the MSDS (Material Safety Data Sheet) for Cadmium (I do work for a chemical company), the LD50 for Cd in rats is 2.3 g/kg and in mice it is 0.9 g/kg. Let's assume humans are more like mice than rats. A gram per kilogram means it would take 100 grams of Cd to have a 50% chance of killing me; I weigh 100 kg. That is a lot of microbes. The author did well to pick Cd, though; its effects are seen much more quickly than those of Arsenic or Lead.

Another backdrop element in the series is the Modhri, an intelligent, telepathic coral symbiote that can gradually take over the actions of most beings. It appears quite capable of taking over the Galaxy, and Frank Compton's main mission is to root out infestations of Modhri Walkers and Eyes. Though there are many of these, there is only one Modhri; it is kind of like the Borg in Star Trek, without the need for technological "assimilation". Of course, there is a segment of Modhri on the Quadrail, which complicates matters, particularly as it is necessarily out of communication with the main Galactic Modhri during the journey.

It interests me that I read this book in two days. The nonfiction book I reviewed immediately prior is about the same size, but took more than a week to read. And it is very well written, even using dialogue very well. Somehow, the best fiction just makes for faster reading than the best nonfiction.

I didn't go to the effort to map out the plot line. The book is about the right size for a 7-turn formula, and the two major plot reversals are enough to confirm my guess. Since the second "cut to the chase" introduced a major new element, we can expect following books of the series to take a different tack in the standing of the Modhri.