This is the seventh book in the series and the first in Which Daisy and Charlie get to meet. If you have not read the The Clockwork Chimera series yet, I would recommend reading that series before this book.
Scott Baron continues the arc he started in book 6, with more and more hints about who is really behind the near and possible future destruction of Earth. Come watch your favorite characters continue to be put into peril and learn more about the plot against Earth and humanity.