In the evening, when the sky was the colour of burnt umber, the factories crawled down the continental shelf to drink.

The Spire is an inhuman artefact, a construction almost three hundred miles high. But it is more than just a big dumb object. Those close to it can look into the future — a future which is going to be arriving sooner than they think, and which is as bad as can be.

In the here and now, Professor Bernice Summerfield, doyenne of twenty-sixth century archaeology and seedy space-port bars, is used to seeing strange things in her rooms. So it takes the unexpected arrival of an angel to get her away from increasingly desperate professional deadlines and off to investigate one of the seven hundred and seventy-six wonders of the galaxy.

However, Benny is not the only one interested in the Spire. A mysterious race of weaponsmiths, a mutogenic assassin and a sect of fanatically anti-religious reptiles all have their reasons for learning — or concealing — the structure's secrets. And, as she struggles to unlock this ancient mystery, it soon becomes clear that the life of an eccentric professor is of very little consequence indeed.