Extremes is told in three narrative threads. One follows Miles Flint, the Retrieval Artist of the overall series title. His job is to track down people who have "disappeared" -- basically, people who have taken on new identities. Flint is approached by a law firm to track down one Frieda Tey, a human Disappeared accused of killing some 200 people by introducing a genetically-engineered virus into an outsystem dome. However, she and her father (who engaged the law firm) claim that the deaths were accidental and she is being railroaded.

Another thread follows Noelle DeRicci, a clich?? "maverick" cop (i.e. she's really good but her career is stalled because she won't play politics) who is assigned to investigate a death at the annual "Moon Marathon", a standard length marathon run on the Moon's surface in environment suits. The third thread follows Miriam Oliviari, a "Tracker" looking for Frieda Tey. Miriam has tracked Frieda Tey over several years, and she has decided that Tey is one of the Moon Marathon competitors.

No prizes for guessing who the murder victim at the Moon Marathon is identified as.

The three threads begin to coalesce once the principals realize that besides the murder the Moon Marathon is being disrupted by an outbreak of a virus very much resembling the virus that killed all the people Tey was accused of killing. Oliviari realizes the same thing, and as her cover identity is one of the marathon medical team, she is forced to deal directly with the virus outbreak -- an outbreak she may know more about than anyone because of her research into Tey's past. So the novel continues, with DeRicci dealing with a very unusual murder and an epidemic to boot, and Oliviari forced to compromise her chance to catch Tey in order to save lives; while Flint is also forced to compromise his Retrieval Artist ethics. All ends in a thrilling space chase.

On one level, it's exciting stuff. The ending is pretty scary and well set up. The basic mystery is interesting. The novel is a whole is fast moving and good reading. But nothing really makes much sense! Part of my problem is just economics -- I simply cannot believe there are enough Disappeared and enough associated legacies and stuff to support the apparently thriving business of Retrieval Artists, and the incredible fees they charge. (Flint, for example, is set for life as a result of a previous case.) Part of it is the overblown villainy of the eventually revealed bad guy. Part of it is the strained setup of the original crime, depending on just too many coincidences. Part of it is the mechanics of the whole thing -- Flint's computer security skills, for instance, which as presented might as well be magic. Part of it is the structure -- the novel is supposed to be a Retrieval Artist Novel, but Flint's Retrieval Artist skills basically never come into play. Read the book quickly without thinking much and I think you'll be entertained -- but pull on any of the dangling threads and the whole thing collapses.

Rauch plays fair with the science and the mystery. Since the reader is privy to information from three different investigators, he or she may well solve plot points ahead of the heroes, but not so far ahead as make the story slow or unsatisfying.

Certainly worth a read in these dog-days of summer.