I think your question may be too general to get good feedback. It's like considering all the ways a story might end, in general. It really depends on the story itself: the plot, the themes the author illustrates, the tone of the story, etc.. I don't know enough about your story with the halflings and the machines to suggest anything appropriate.
What are your goals with the story?
If you want ideas, you could browse through all the story archives and see what other authors do sometimes, in similar stories.