I think the lack of a "to be continued" is part of what annoys me most about that ending. I could have sworn this wasn't supposed to be a story split into two parts, based on things I read a while back, but that is exactly what this movie felt like. Part One and Part Two would have made far more sense to me. (It's very possible that I misread the thing I read awhile back, but that is how I went into this movie.)