Lydian skies could be spectacular, mixing a palette that ventured from the palest of streaky greens unveiling the sun in at daybreak, to full-bodied violets, lilacs, and lavenders that turned the western clouds into towering castles of light in the evening. One of the biologists with the Kermes had put forward a theory attributing the displays to photodissociation in the upper atmosphere of exotic molecules produced by the planet's lush and varied flora, which made even the tropics of Earth seem unassuming in comparison. The biologist had been challenged by the mission's head physicist and head climatologist, both of whom claimed the subject as belonging rightfully to their domain, and a motion was already being filed back on Earth for the issue to be brought before a scientific arbitration court.

Chelm was seldom drawn into such things. As an archeologist, his field was more self-contained and defined, and territorial disputes with other disciplines tended to be rare. Colleagues warned him that invisibility equated to obscurity, and having a low political profile was tantamount to committing career suicide. Wilbur Teel, his section head, would come poking around, looking for possible areas of overlap that could be used to pick a fight with the linguists or paleo-sociologists, maybe, and hinting that Chelm could help his future promotion prospects by taking a more aggressive stance himself. Chelm sometimes wondered if perhaps he was too accepting and passive. But the thought of a future supposedly broadened by getting involved in the perennial rivalries and infighting that went on among the upper administrative echelons back on Earth simply didn't excite him. He wasn't, he supposed, if he was honest with himself, really that competitive by nature--not that he would have admitted it to the ship's psycho-counselor. The fact of the matter was that he liked his work and its challenges, especially when it took him out in the field and among the natives. Times like right now, for instance.

He sat on the end of one of the log pilings supporting the boat dock that formed the lower level of Ag-Vonsar's house, watching the old man scrape an upturned wherry-like craft that had been hauled up for cleaning and repair. The house was built on stilts like the rest of the settlement at the bottom end of the lake, with storage space immediately overhead, the general living area above, and sleeping rooms above that again. The houses were all interconnected by stairways and bridges to form what was essentially a village over the water. The workmanship was rich, ornate, and precise, bringing to mind a combination of ancient Meso-American pattern work and colorful Chinese intricacy. Besides making boats, Ag-Vonsar also constructed sluice gates for the system of water channels and locks that irrigated the surrounding area and allowed the level to be controlled during the season when the river feeding the lake was in flood. The dry dock and shop that he maintained for this heavier work were part of a boatyard built along the shore.

What had first attracted Chelm's interest to this place was a long, low, square-formed block protruding from a hillside into the water to provide a breakwater and jetty bounding the upper end of the yard. He had assumed it was cut natural rock, until closer examination showed it to consist of an artificial material similar to concrete. Some Lydian structures, such as temples, aqueducts, and bridges in cities and other locations that Terran exploration teams had visited did, it was true, use forms of concrete. But the type was reminiscent of the kind the Romans had developed: tough, virtually immune to demolition in some instances, deriving strength from the filiform binding of carefully blended minerals. The block at the upper end of the lakeside yard, however, was of coarser composition, reinforced internally by metal ties in the style of Terran patterns that had come into use millennia later--as if the arrival of heavier industry had rendered the earlier reliance on finer-grain chemistry superfluous. Could it be that an advanced culture had existed at one time on Lydia, and then vanished practically without trace? If so, what kind of calamity could have overtaken it?