Firefly is Sally Beckdale. With the aid of nano technology developed by Lisa Yashioko (The scientist of the team), Firefly has the ability to miniaturise. Together with her flight pack she is able to access areas with the speed and agility unmatched by a conventional firefighter.
As with the fire engineer she has a wrist mounted extinguishing device, plasma protective helmet and fire resisting suit.
The Origin of Firefly is contained in the first issue of the Journal of The Fire Engineer, which can be downloaded from the Downloads section of this site.