While digging on his farm near Fort Moxie, N.D., Tom Lasker discovers a yacht, complete with sail. It looks almost new, but no one knows how it was buried there. The yacht has other oddities as well, such as writing in strange characters and the lack of a registration number.

Max Collingswood, one of Tom's friends, takes a sample of the sail to Colson Laboratories for analysis. When April Cannon performs the tests, she is astounded. The material consists of a new element with an atomic number of 161 -- something well beyond modern technology. It's also extremely resistant to wear and other damage. Fibers from the mooring cables are found to come from spruce trees, which have long since disappeared from the area. But 10,000 years ago, Tom's farm was at the bottom of Lake Agassiz, a great inland sea larger than all the Great Lakes combined. April hypothesizes that the yacht once sailed the lake, and that it could be evidence of extraterrestrial visits.

Max and April hire a ground radar team to search for more artifacts, and they find a large circular structure buried in the ground. Excavation reveals a building made of the same material as the yacht. Before more work can be done, word of the discovery leaks out, and visitors flock to the site, making investigation more difficult. Meanwhile, the stock market is falling because investors fear the implications of the new material. And the newly found roundhouse proves to have capabilities no one dreamed of, capabilities that prove its extraterrestrial origin...

In Ancient Shores, Jack McDevitt integrates a fascinating scientific mystery and details its global, political and economic consequences. He also manages a particularly effective portrayal of the discovery's effect on the local community -- while they first embrace the discoveries, soon Fort Moxie's citizens become divided as the influx of visitors changes the town's character.

McDevitt also chronicles the interests of the Sioux, who own the land where the roundhouse is located -- in fact, several of the tribe members are among the novel's strongest characters. Throughout the story their motivations are clear and consistent, and McDevitt evokes genuine respect for their position. The resolution of their struggle to maintain their land leads to a particularly dramatic climax.

Less successful is McDevitt's description of the economic panic the discoveries create. The stock market collapse is plausible in the short term, until it becomes clear that duplication of this material won't happen very soon. McDevitt also takes some artistic chances with the novel at various points, and on the whole he pulls off most of them. Despite a crisis that seems unjustifiably contrived, Ancient Shores is well worth reading.