In a city that was, relatively recently, stolen by giant bats, a young man wakes up in a holding cell. There's a guard standing watch, though a rather scrawny one.
The monster hunters go quiet.
The Apathetic Secretary looks, for once, engaged. "Nobody quite knows. It's like a bat, they say, but very big, and deadly as anything. It preys on Londoners in general, but its favorite prey is hunters - specifically, Vake-hunters. People come in and say they're after the Vake, and next thing anyone knows they've vanished without a trace."
...he laughs. "Wow, a giant bat that eats people. Why does anyone ever admit they're going after it, then?"
"How does anyone know where to find it if it kills you as soon as you admit to looking?"
"Might as well, I'm all curious now!"
He snickers. "Thanks. I'll keep that in mind."
At this point he's getting kind of hungry but that seems like a thing he can figure out later. He knocks.
"Somebody told me you know things about the giant bat that eats people!"
"You met it, right? What happened?"
The Naturalist smirks. "Straight to the point, I see. Well, I was fascinated; I was a chiropterologist, prior to a change in fortunes, and a giant bat seemed interestingly novel. How did it fly? What genus did it most closely resemble? And so I learned everything I could about the beast through the ordinary measures - searching various libraries both public and private, asking others in the field - but it wasn't enough. I went to the Department of Menace Eradication and asked the monster-hunters, 'what can you tell me about the Vake?'"
The coffee arrives. It's absolutely terrible. The Naturalist sips his without seeming to notice. "They were more or less useless. But as I was headed back to the University, I was attacked by nothing less than the Vake itself. The Vake was nothing like an ordinary bat; its wings were tipped with terrible claws, and its teeth were more like the fangs of a wolf or tiger. Alongside other anatomical differences, of course, but those were the ones most interesting to someone without a chiropterological background. But as it savaged me, I felt a bottle slip from my pocket - a special, Correspondence-etched bottle containing an Aeolian Scream, which I had been holding onto for a friend. When it shattered on the pavement, the scream was released, and as it echoed around me the Vake was stunned. It was, in fact, stunned long enough for me to escape."
...wow, that sure is a substance. Is coffee always this bad? He can't remember.
"Huh," he says. "Lucky you. And you haven't seen it since?"
He laughs. "Oh, I certainly have. The very next time I left my office, I was attacked again - but I was prepared, and had purchased another Scream. After this second attack, I designed a special device which emits a loud and terrifically high-pitched noise, inaudible to our ears but absolutely hateful to bats, and set up shop in this house in the marshes. The device hangs above our heads-" he points to an arcane-looking contraption built into the room's ceiling "-and if the Vake approaches, it will most certainly wish it hadn't."
He laughs. "Oh, good thinking!"
"To be perfectly honest with you I hadn't thought that far ahead. Let's hear it, anyway."
"Well, the first thing you would need is a mandrake root. They don't kill with their voices, as the legends say, but they do hurt. Anything that can hurt a human with its voice will most certainly hurt a bat. Once you've acquired the root itself, you'll need to treat it with wine and teach it to sing."
"That sounds like fun even if I'm not using it to hunt giant bats, really."
The Naturalist chuckles. "The second step would be to acquire one of the Vake's own teeth, and fashion it into a weapon to use against it. Its skin is fantastically tough, you see, and only another of its kind could penetrate. My research indicates that its teeth grow back, you see, after they're lost - and after four thousand years of wandering the Neath, it must have lost a few."