The Engines of God by Jack McDevitt

I'd not come across this author's work until this one was chosen by the Classic SF discussion forum as a monthly read, but it sounded interesting enough for me to get hold of a copy.

The Engines of God does indeed have a classic SF plot: ancient alien remains are found scattered around the galaxy following the discovery of faster-than-light space travel. Most of them are elegant sculptures – including one in our Solar System on Iapetus, a moon of Saturn. But more puzzling are some starkly contrasting blocky structures, to a rigid arithmetical formula, close to planets which have, or had, civilisations apparently incapable of space travel. Furthermore, these structures seemed to be linked in some way to disastrous collapses of the native civilisations.

Archeologists are on the case, trying to discover more about the various aliens and their relationships. But their best hope – a well-preserved ancient temple on a planet where the natives have died out – is threatened by a terraforming project to create a new Earth, as the old one is heading steadily into the environmental disaster zone. 

The heroine of the tale is space pilot and amateur archaeologist Priscilla Hutchins, who works alongside the professionals as they battle with deadlines and try to grasp the significance of what they are finding. The plot steadily widens in scope and accelerates in pace as more discoveries are made, and there is a thunderous finale in the best traditions of wide-screen SF when what had appeared to be an abstract historical problem becomes horrifyingly real.

The book has some flaws: the story contains some padding in stretching to over 500 pages, for example detailed descriptions of the play-acting the characters get up to while on a long voyage. There is also an irrelevant and rather long section concerning a visit to a planet that ends disastrously, but which doesn't advance the plot at all. And while the characterisation is generally adequate, the heroine never really comes alive and the treatment of all of the female characters is a bit clichéd: they are all amazingly attractive, and Hutchins is repeatedly told by admiring men just how beautiful she is. Despite these criticisms it is a gripping tale, its hugely ambitious plot the first in a long while that has managed to spark in me some of the "sense of wonder" which drew me to SF in the first place. Recommended.

I see that although this was written as a stand-alone, several other tales subsequently appeared which are set in the same universe and feature the same principal character. More to add to my reading pile!