It was unfortunate, though, she thought, as she waded through tomes and scrolls.  Luna had always been the theoretician.  Celestia never really understand the fine points of how her magic worked, she just relied on her instincts and emotions, while Luna was colder and more calculating.  While it was true that thousands of years of practice had left Celestia the most skilled unicorn in Equestria, at heart she was a pegasus, decisive but impatient.  Had it not been for her sister’s subtle jabs, she surely would have let the matter rest; as it was, every time she felt like quitting the project, she simply went to her sister’s chambers, took one look at the bed, and renewed her research, even though her hopes were falling like the leaves on the trees.