Complex sentence: The third book, "Darkness Falls", is set to be published on 3 September 2013, while the fourth book, "The Broken Path", is set to be published on 11 February 2014.
Split into simpler sentences: The third book, "Darkness Falls", was published on 3 September 2013. The fourth book, "The Broken Path", is set to be published on 11 February 2014.