Saints is the companion novel to Boxers and slightly shorter. It tells the story from a young Chinese girl who converts to Christianity during the Rebellion. It was interesting to see the same events that played out in Boxers seen from the other side, but all in all, I don't think this was as strong as Boxers was. I will say, though, that while you could probably read either first, I'd go with this one last since it does give the final piece to both books' endings.