Colleen Gleason's Stoker & Holmes

The Clockwork Scarab
There are a limited number of excuses for a young, intelligent woman of seventeen to be traversing the fog shrouded streets of London at midnight. A matter of protecting one’s life or preventing another’s death are two obvious ones.
But as far as I knew, I was neither in danger for my life, nor was I about to forestall the death of another. 
Being a Holmes, I had my theories and suspicions as to who had summoned me and why.
The handwritten message had told me that its author was not only female, but one of high intellect, excellent taste, and measurable wealth. Its content had been straightforward:
Your assistance is requested in a most pressing matter. If you are willing to follow in the footsteps of your family, please present yourself at the British Museum tonight at midnight. Further direction will be provided at that time.
As I looked at the letter, I saw so much more than those simple, yet mysterious words.
Lack of name and address, no seal or watermark—the anonymous sender hand-delivered the message.
Heavy creme paper, neat feminine handwriting lacking embellishment, and free of ink blots and errors—an intelligent, pragmatic woman of considerable wealth.
Faint perfume scent—expensive but in excellent taste; from the incomparable Mrs. Sofrit’s on Upper Bond.
Traces of rice powder and a smudge of silver glitter—sender is involved with the theater, likely La Teatre du Monde in Paris.
Big Ben tolled as I walked along the middle level of New Oxford-street, the soft yellow glow of the streetlamp cutting into the ever-present fog. I heard a soft scuttling sound followed by a low, dull clank and slowed to listen, a hand covering the weapon at my waist as I peered into the dim light.
I had borrowed from Uncle Sherlock the Steam-Stream gun that hung in my nonfeminine belt over loose gabardine trousers. One pull of the trigger would release a puff of searing air, a concentration of burning steam. Enough to incapacitate a grown man or slice through his skin, my uncle had assured me. The beauty of this steam-powered gadget was that it never needed to be reloaded.
Not only was I armed, but I was suitably attired, for bustles, crinolines, and tight sleeves are cumbersome and impractical for a pedestrian on shadowy streetwalks. Between the weight of the layers of my normal ensemble and its incessant rustling (not to mention the length of the dratted skirts), I would have been a walking target for anyone from whoremongers looking to find a new girl or to the footpads who lurked in shadow—or to any dangers that existed for a tall, gawky, yet intelligent young woman who’d been cursed with the beak-like Holmes nose.
I felt confident I was prepared for whatever dangers I might encounter.
One of the self-propelled Night-Illuminators trundled below on its four wheels. I looked down from the raised walkway on which I stood and watched its welcome glow putter through the shadowy night. The cool air stirred, bringing with it the familiar scents of dampness, dry ether, burning coal, and sewage. Below, at the ground level, I heard other common sounds of night: the clip-clop of hooves, the rattle of various wheeled conveyances, shouts and laughter and, threaded through it all, the constant hiss of steam. 
Steam: the lifeblood of London. 
I paid two pence to take a street-lift to the middle level of the block, where it was ostensibly safer to walk alone. But at midnight in London, I wasn’t certain that any street level was safe.