The main action begins with Faye's first job as a proctor, which happens to correspond with an outbreak of killer androids, who murder several other proctors. Faye herself is saved only by a mysterious entity which seems to be a movable wormhole. In quick succession, Faye is kidnapped by members of the Technocracy's Admiralty (who are interested in the "wormhole"), rescued by Festina Ramos of Expendable, and investigates the police investigation into the killer android episode. This finally leads to an interlaced series of confrontations with the past: Faye's past, the planet's near past, and its mysterious previous occupants in the more distant past.

The book is action packed. The early pages seem to promise a story concerning the fairly interesting political concept of the Vigil, tied in with, perhaps, Human/Oolom relations and Faye's personal growth. While these features aren't precisely forgotten, they tend to be submerged under the fast-moving plot which soon involves a different Divian species, trade negotiations, ancient alien archaeological sites, new plague outbreaks, and some very old crimes.

Gardner piles quite a few concepts on top of each other, and for some time I was keeping a list of outrageous coincidences on which he was supporting his plot structure, as well as some unreasonably mystical technology. But I was unfair. Most of his coincidences turn out to be not so coincidental after all. As well, the tech is quite well explained and all is resolved in a fairly tightly constructed denouement.

This is definitely a fun read, and an interesting book with plenty of clever ideas and pretty much non-stop action. On the negative side, even though the coincidences are generally well explained, the elaborate edifice of motivations and plots tends to give the book an artificial feel and tends to make Faye, the central character, seem to be a pawn in a story really involving much different, non-human, entities. Thus, the final unfolding of the story, even if reasonably logical, isn't quite as personally involving as one might have hoped. As well, the high tech mysteries, while once again well explained, have a deus ex machina feel to them, at least at the Human/Oolom level. Furthermore, the main human villains (including the Admiralty thugs who kidnap Faye), act in very stupid and dangerous ways. Some of this is explained away, but some seems to be necessary only to propel the book's plot.

Thus, on the whole I can recommend Vigilant as an enjoyable, fast-moving, off-planet adventure, with the caveat that character development and general plausibility sometimes take a back seat to plot requirements. At the same time, Gardner clearly can do characters well, and Faye in particular is a well-depicted, less than perfect but still likable viewpoint character. Gardner's Technocracy seems an interesting universe in which to set stories, with an intriguing if basically implausible central law: no killer of another "sentient" can ever engage in interstellar travel. I'll look for his other novels.