A Riddle in Bronze

we may face outright hostility."
My heart sank at this news, for despite the strange events I'd witnessed with my own eyes, I could not imagine myself describing them to an incredulous aristocrat. We would be treated like explorers with news of the discovery of a solid gold mountain. I swear it's true ma'am, and the treasure map can be yours for no more than five guineas.
"Come now, it won't be that bad," said Roberta, smiling at my pensive expression. "After all, how long did it take me to convince the sceptic in you?"
I knew she was right, but at the same time I felt like a child wading into deep waters for the first time, while a well-meaning parent stood safely on the shore and assured them that swimming was easy. I felt a deep sense of unease and foreboding, and no amount of honeyed words were going to dispel my fears.
We reached the station, where we boarded the underground train. This was a new experience for me, sitting in a rattling carriage with its own gas lanterns as we plunged into the tunnel that passed beneath the very streets of the city. Immediately, we were beset by cinders and smoke from the engine, and the air was unbearably foul despite the ventilation shafts that I knew rose to the surface above. The walls of the tunnel sped past, faster than a man could run, the soot-stained brickwork close enough that I could have reached out and touched it. Above, crowds would be thronging the streets of the city, clogging the thoroughfares, and I marvelled at the ingenuity that had placed an entire railway underground.
The train slowed soon after departing the station, and we reached a new tunnel under construction. Labourers were working in dim, hellish conditions, while ragged-looking children hauled away rubble in wooden carts. The air rang with the sound of picks and shovels, drowning even the regular chuffing of the steam train and the rattle of the carriages. As we passed the area, I happened to glance into the dark, cavernous mouth of the new tunnel, still half-built and shored up with dozens of planks. In the far distance I thought I saw a flicker, as if lightning had somehow managed to enter the tunnels, but when I blinked it was gone. I put it down to a trick of the light, and did not mention it to Roberta.
Once past the workings our train sped up again, and we soon alighted at the end of the line. Here, we emerged at Westminster Bridge station, and we strolled to Bridge Street to obtain a cab. On the way I dusted at my coat with a handkerchief in a vain attempt to shift the soot from the train. Alas, I only succeeded in distributing the substance around my person. I glanced at Roberta, who wore the garb of a labourer, and gave a rueful smile.
The cab bore us past the busy vegetable markets and on to a street in Covent Garden, where it drew up outside a row of impressive Georgian residences. They were the sort of houses where a liveried butler met important visitors at the front, perhaps with a footman or two to help guests out of their carriages, while everyone else gained access via the rear.
Roberta paid our driver, and we carried our haversacks down a narrow alley between two of the houses. At the rear we found a yard, where a scullery maid was emptying a bucket down a drain. She glanced at us, startled, and then her face cleared. "You're the rat catchers, aren't ya?"
"That's right," said Roberta, giving me a warning glance.
"If you'll follow me, Miss, I'll show ya both indoors."

Chapter 9
"Rat catchers?" I whispered to Roberta, as we followed the maid.
"Do you think Lady Snetton would tell her staff the real reason we're here?" hissed Roberta. "An article in the Gazette with that manner of gossip would ruin her reputation."
I saw her point. Staff were loyal to a certain extent, but a newspaper reporter with a spare shilling could extract juicy titbits at will. The daily papers were full of gossip, with only the most cursory effort at concealing the identity of those in the firing line.
We entered through the kitchens, where preparations for the evening meal were in full swing. A portly cook was tending pots and pans bubbling on a large stove, and as she noticed our presence she turned her ruddy face to us, eyes gleaming with suspicion. "What do you want?" she demanded. "Annie? What you doing bringin' these people into my kitchen?"
Annie bobbed her head. "Beg pardon, Mrs Watson. They're here about the rats."
The cook sniffed. "They don't look like no rat catchers to me."
"Nevertheless, we do have an appointment with Lady Snetton," said Roberta. "Would you have someone show us up?"
"Why would her ladyship deal with the likes of you?" demanded the cook. "Be about your business, and then be off with you."
"We come recommended by one of Lady Snetton's closest friends," said Roberta, persisting despite the cook's brusque manner. "We were specifically told to report to—"
"There's no stoppin' you, is there?" Mrs Watson gestured impatiently with her ladle. "Annie, take 'em up, but on your head be it." Then, having divested herself of all responsibility, she turned her full attention to the stove. "Bloomin' trades and their bloomin' airs," she muttered, loud enough for all to hear. "What's the world comin' to?"
"If you'll follow me," said Annie, keeping her voice low. As we left the kitchen, she offered further explanation. "Mrs Watson's put out, see? She's lost two helpers this week, and she's having to mind everything herself."
"Lost two helpers?" I repeated. "Whatever happened to them?"
Annie snorted. "They believed they saw ghosts, sir, and ran off without giving notice. Too fanciful by half, if you ask me."
The maid seemed like a solid, dependable sort, and the scorn in her voice was obvious. I wondered whether she'd be so sceptical had she