Seeker (Alex Benedict - Book 3) by Jack McDevitt
The Nebula-Award winning novel from the multi-award winning SF master Jack McDevitt. Also a Campbell Award finalist. Third in the acclaimed Alex Benedict series.
When Alex Benedict, interstellar dealer of antiquities, examines a seemingly unremarkable artefact, he is convinced it is from the infamous Seeker - a transport ship which fled the religious dictatorship in 27th century America. With the help of his pilot, Chase Kolpath, he follows a deadly trail to the Seeker, now strangely adrift in a system barren of habitable worlds.
But their discovery raises far more questions than it answers, drawing Alex and Chase into the very heart of danger.