Seeker is the 3rd in Jack McDevitt's Alex Benedict series. It won the Nebula Award for best novel in 2006. The 2nd book was definitely the weak link in this trilogy. I liked this one much better.
from the back of the book:
Thousands of years after an entire colony mysteriously disappears, antiquities dealer Alex Benedict comes into possession of a cup that seems to be from the Seeker, one of the colony's ships. Investigating the provenance of the cup, Alex and his assistant Chase follow a deadly trail to the Seeker-strangely adrift in a system barren of habitable worlds. But their discovery raises more questions than it answers, drawing Alex and Chase into the very heart of danger.
I bought the paperback new, because I didn't want to wait the interminable length of time before I would come across it at one of the local used book stores. If there are further books in this series I'll buy the hardbacks new. I am thoroughly enjoying this author. There is a review here that fairly well sums up my own opinion. Here's an excerpt from the end of the review:
In many ways, Seeker is a curiously old-fashioned book. Ten thousand years in the future, mankind has -- in contrast to the futures of more flamboyant writers such as Charles Stross and Cory Doctorow -- hardly changed at all. Colonies settled are thoroughly Earth-like, people by and large look and behave exactly as they do today (there are no implants, uploads or downloads) and there AIs are basically WASP holograms.
But that very element of familiarity goes a long way toward explaining McDevitt's popularity. He is regularly compared to Arthur C. Clarke, and his love of exploration and rationality are indeed reminiscent of Clarke, but in his solid championing of decency and the ordinary man prevailing, the author he is most like is Clifford D. Simak. In a world that is often -- especially to Americans -- unstable and threatening, that innate decency is more appealing than ever, and explains some of Seeker's success.