This is a very difficult question to answer. On one level, it was intentional, simply because the story line moved back to the worlds of the Alliance. On the other hand, I did not write this to 'purposely' move away from Earth. The adventure of the Matrix books weaves an epic tale with a broad scope. It is not a question of it necessarily moving away from Earth, but rather where the story line unfolds as it unfolds.
Distance is a relative concept in more ways than one.
Like many writers, my inspiration comes from within. When I am reading for my own enjoyment, my tastes tend to be eclectic- ranging from romance to crafts to science to mystery to the classics to just about anything that intrigues me. Since I write in all the genres, my research methods vary depending on what I am writing. The juxtaposition of the Regency time period with the alternate universe was incredibly tricky. The tone of the dialogue between Lilac and Rejar had to be just right to work for my modern day reader.