I am looking for a particular Jack McDevitt novel, I believe set in the Alex Benedict series. It may have been a subplot or the main plot, but they find a toy-like spaceship, only to uncover near the end that it is actually a real spacecraft, used by a small butterfly-like spacefaring race.
I have looked at all my Jack McDevitt Academy and Alex Benedict series books, of which I have all except Cauldron, and I don't think it is Cauldron.