Seeker by Jack McDevitt
This is an Alex Benedict story which takes place chronologically after his book Polaris.
A woman brings an oddly decorated cup into Benedict's office for an appraisal, thinking it might be worth a few dollars.† Benedict is a dealer in antiques and antiquities, with a talent for finding obscure treasures.† A scan of the cup dates it as being 9000 years old.† (For those not familiar with this series of books, that puts the cup 600 years in our future.)† It turns out the inscription is in an obscure dead language, English.† It appears that the cup is connected with some early starship, but an exact translation of the ship's name isn't possible.
Eventually, investigations conclude it belongs to the starship Seeker, which is legendary among historians of that long-gone era.† It was one of two ships used by a group of dissidents who left Earth to form a colony on a planet whose location was unknown to anyone else.† The colony has never been heard from again during the following 9000 years.
Benedict - or more precisely, his assistant Chase - tries to follow a very long, sparse and sketchy trail to find the Seeker, and maybe the colony.
Chase's search leads her into the worlds of "the Mutes" - the only other technological civilization humans have found to date.† They are called "Mutes" because they evolved with telepathy and, therefore, don't speak.† While they are vaguely humanoid, the physical differences between humans and Mutes make each species find the appearance of the other unpleasant.† Although the two species have had conflicts at times, neither has intentions to conquer or wipe out the other.† Our introduction to the Mutes may not be as extensive as some readers might like, but there is interesting material here.
Meanwhile, someone is trying to stop Benedict and Chase from pursuing the trail of clues Ė including attempts on their lives.
Itís an interesting tale with elements of adventure, treasure-hunting, exploration, mystery, other cultures, and a view of the future.† It doesnít have the feel of a detective story or the pace of a thriller.† The clever methods devised to learn something useful from each small clue should appeal to those who enjoy mysteries.
Iím reluctant to say much more, so that each reader can unravel the story for himself.