I have been on the lookout for this book and also the first book in this series,  Marrow, for some time now. So, as my usual M.O., when I saw it I bought it and now it awaits on my bookshelf for the time I will be able to read it, which like everything else will hopefully be sooner rather then later. The Wikipedia entry for The Well of Stars is vague, but from what I can gather, the story follows a group of people on a ship, and once on board they stumble upon a hostile alien race in a forbidden Nebula, from which they have to fight to stay alive and escape. Worse yet, the creators of the ship are also in hot pursuit and apparently looking for vengeance. But vengeance from what and how this group came to be in procession of this ship is unclear. I guess these answers are most likely to be found in the first book.