Girls with Guns is the 14th Proposed Serial of Spectral Shadows. It is preceded by Serial 13 - A Ghost in the House of Spectral Shadows and succeeded by Serial 15 - Around the Universe in 80 Days. This serial is currently not in the works, and the only material available is the summary from the Synopsis Page.
The summary - albeit a very short one - is as follows:
Super heroes, super spies, super detectives, rock stars and Omman Knights in training are all called into action to stop a power hungry reptilian crime lord from selling the planet Cygnus out to alien humans.