“Watch the candles.” It was the skull’s voice in my ear. “Watch their light.”

And sure enough, the candles were twitching, responding to a minute agitation of the air. I could feel the hairs on my arms rise, my breathing tighten. My ears hurt, as if I were descending in an elevator, too far, too fast. I closed my eyes and listened. From somewhere came a cry of mortal pain.

I opened my eyes. “George?”

An almighty bang. I jumped where I stood. The noise echoed up the staircase, was swallowed by the dark. I knew it had come from below, from the basement. The candle auras had stilled; they gleamed like the irises of sightless eyes.

“George?”

No answer. I cursed, drew my rapier, stepped out of the circle into the freezing dark. I crossed to the banister, and looked down.

Two flights below, something was coming up the stairs. I could see dark smears appearing on the steps. Whatever made them was invisible, but it moved slowly, spattering them as it went, extinguishing each candle as it passed.

Darkness in the basement; no red glow from George’s lantern. I gripped the banister, craned my head out to see if I could—

The last candle on the basement stairs died. Gleams of wetness appeared on the floorboards of the hall. Was that a cloudy hand gripping the banister for support…?

No—there were two hands, one some way behind the other. And now first one, and then the other, flowed suddenly forward, picking up speed, angling around to the flight that would bring them up to me.

“Lucy…” It was the voice from the jar. “I’d step over here sharpish, if I were you.”

Still I clutched at the rail. How cold it was, tearing at me through my gloves. It was so hard to think of moving. My limbs were far too heavy, my body somehow far away.

On the stairs, two racing, cloudy forms dragged darkness up behind them like a cloak. Fast as you could snap your fingers, the candlewicks they passed snuffed out.

“Bet Holly would have the wit to get back to safety,” the skull remarked.

Something needling jabbed inside me; indignation cut through ghost-lock. I shoved my body backward, threw myself across the landing. Tripping over the chains, I fell into the circle, on top of my bags, and sprawled there as two shapes erupted past me.

They moved in utter silence, pale other-light flowing off them in swirling ribbons. The first, so small and fragile, the cloudy imprint of a child. How thin the body was, how slight the shoulders! You couldn’t see any details. It was only as solid as a candle flame, and the lower half tapered into nothing. The head was bowed; it thrust itself desperately forward, tiny hand trailing on the banister.

And now, pooling out of the darkness at its back—a second shape, luminous also, as if woven from the same substance as the first. But larger, much larger, a bulky adult form, and the other-light streamed around it more darkly. Again, no sense of the face or appearance, only of a great arm reaching out, a bull head swinging to and fro.

The child’s form passed by, darting up the next flight with the pursuer closely following, and away they climbed toward the third floor. Out went the candles above me, quick as blinking. Cold followed in their slipstream and with it, sound: a thin sucking movement of dead air. They were gone. I waited, hunched forward on my knees, teeth clenched, lips bared. Still the cold deepened; and now, from high in the house, came a final dreadful screaming. Something fell past me. I sensed its bulk, I heard the rush of air beyond the banister, and tensed, waiting….But there was no sound of impact from below.

It was only then I saw the black, wet marks that defaced the boards beyond the chains. The straggling stains of bloody, running feet.

I was still there, crouching, staring at them, a minute or two later, as the temperature grew warm, the scent of smoke and candle wax trailed into the circle, and I heard the calm voice of Lockwood calling from above to say that the manifestation was over.

The footprints lingered for one hour and seventeen minutes. George timed it on his watch. They were formed of a thin black ectoplasmic substance that radiated extreme cold. When Lockwood touched one with the point of his rapier, it steamed and spat fiercely, sending snakes of black vapor coiling up the silver blade. It was an interesting phenomenon. George mapped them; I made sketches of some of the clearer prints, the ones that weren’t too faint, or too awash with blood.

“They’re small feet,” Lockwood said. “Not tiny, like a young child’s, but pretty slim and slender. Must be Little Tom’s, not Robert Cooke’s.”

“We should measure them, really,” I said. “But I don’t want to get too close.”

“Good point, Luce.” He wore gloves, and had pulled a dark blue scarf out of his bag, his only concession to the chill on the stairs. “I guess we could do a comparison….Who’s got the smallest feet among us?”

“Holly has,” George said, without looking up. “No question.”

I spoke through gritted teeth. “She’s not even here.”

Lockwood nodded. “You’re right, George. They are petite, aren’t they? I bet they’re about that size. We should measure Holly’s feet tomorrow.”

“On it.”

“Of rather more importance,” I said tartly, “is where to look for the Source of all this. Where do we think Little Tom died?”

In the ordinary way, the best place to look for a Source is near where the death took place, but this manifestation presented problems in that regard. Even our surveillance hadn’t helped much. The servant had first been stabbed in the basement, and the haunting had certainly begun there, with a sudden ferocious blast of energy that sent George flying in his circle and his lantern crashing against the wall. He hadn’t seen the two figures, as I had. Lockwood, waiting at the top of the house, had glimpsed them briefly. As they reached the attic, the shapes—moving fast—had seemed to merge. Then there’d been the deafening scream—then nothing. But I’d heard something falling through the air.

“If Cooke pushed Tom off,” George said, “as Lucy reckons, he would have died when he hit the basement floor.”

“Unless he was already dead from his wounds,” I said. “Poor little guy.”

“So the Source could be at the top or the bottom,” Lockwood said. “We’ll look tomorrow. And let’s have less of the ‘poor little guy,’ please, Lucy. Whatever he was in life, Tom’s ghost is part of this dangerous haunting. Think of what happened to the night-watch kids.”

“I am thinking of them,” I said. “And what I’m also thinking of, Lockwood, is that horrible monster chasing the child. Cooke’s ghost. That’s the evil driving this. That’s what we need to tackle.”

Lockwood shook his head. “Actually, we don’t really know one way or the other. We’ve got to be careful with all Visitors. I don’t care if a ghost’s friendly, or needy, or just wants a big cuddle. We keep it at a safe distance. All the big agencies follow that policy, Holly says.”

I didn’t intend to be angry. Basically I knew that Lockwood was right. But my emotions felt stretched right then; it had been a long night—and, back at Portland Row, a long few days. “This ghost is a lad being chased to his death!” I snapped. “I saw him as he passed; he was running for his life. Don’t shrug at me like that! He was so desperate. We’ve got to feel sympathy for him.”

That was a mistake—I knew it at once.

A light in Lockwood’s eyes flicked out. His voice was cold. “Lucy, I don’t have sympathy for any of them.”

Which, let’s face it, was a bit of a conversation killer. The argument stopped there. Because, like the closed door on our landing, the circumstances of our leader’s past were both un-ignorable and impossible to tackle. His sister had died by ghost-touch. His sister. When that subject came up, there wasn’t really anything more to say. So I dutifully shut my mouth and hung around with the others, until, at around one thirty-four in the morning (George timed it), the plasmic footprints grew faint, then softly luminous, then faded clean away. Those footprints had the right idea. We more or less did the same.

She may have made great sandwiches, and she may have had small feet, but at least I could console myself that Holly Munro was deskbound. She didn’t wear a rapier. She didn’t do what I did, going out nightly and risking her life to save London. This knowledge enabled me to hold it together when I got home to discover she’d been in my bedroom and, in a spasm of brisk officiousness, tidied all my clothes.

I meant to mention it to her (calmly, politely, in that way we had) the following morning, but it slipped my mind. By the time I got up, there were a lot of other things going on.

When I came into the kitchen, Lockwood and George were clustered around the table like it was a pretty new assistant, reading a copy of the Times. Holly Munro, cheerfully immaculate in a cherry-red skirt and crisp white blouse, was doing something with the salt bin behind the kitchen door. She’d had it installed to replace the usual mess of bags and canisters we kept there. I eyed her skirt as I came in; she eyed my saggy old pajamas. George and Lockwood didn’t look up or acknowledge I was there.

“Everything all right?” I said.

“There’s been trouble in Chelsea overnight,” Ms. Munro said. “An agent killed. Someone you know.”

My heart jerked. “What? Who?”

Lockwood glanced up. “One of Kipps’s team: Ned Shaw.”

“Oh.”

“Did you know him well?” Holly Munro asked.

Lockwood stared back down at the newspaper. We’d known Ned Shaw well enough to dislike him, with his close-set eyes and unkempt mane of curly hair. He’d had an aggressive, bullying nature. Our hostility had even brought us to blows, though Lockwood had fought alongside him in the ‘Battle in the Graveyard’ at Kensal Green Cemetery. “Not really,” he said. “Still…”

“It’s awful when that happens,” Holly Munro said. “Happened to me at Rotwell, more than once. People I’d seen in the office every day.”

“Yeah,” I said. I shuffled around to the kettle. The kitchen was too small with Holly in it. It was hard to move about. “How did he die?”

Lockwood pushed the paper away. “Don’t know. It’s only mentioned at the end of the article. I think word had just come in. The rest of the news is no better. The Chelsea outbreak’s getting worse, and there’ve been clashes, people protesting about being forced to leave their homes. Police on the streets are having to deal with the living now, not the dead. The whole thing’s a complete dog’s breakfast.”

“At least our case is going smoothly,” Holly Munro said. “I hear you did very well last night, Lucy. It sounds like a terrifying ghost that badly needs destroying. Would you like a whole-wheat waffle?”

“I’m all right with toast, thanks.” Our case. I pulled back a chair, scraping it across the linoleum.

“Should try one,” Lockwood said. “They’re yummy. Okay. The plan for today: our aim is to all get back to Hanover Square after lunch and hunt for the Source before it gets dark. Our client is impatient. Believe it or not, Luce, Miss Wintergarden’s already been on the phone, ‘requesting,’ in her own delightful style, that I personally update her about what we’ve discovered so far. I’ve got to nip over to the hotel where she’s staying now and give her that briefing. Meanwhile you, George, are going to head back to the Newspaper Archives to get more details on the murder. You reckon there must be more info out there.”

George had been scribbling with a felt-tip pen on our Thinking Cloth, writing out a list of names: Mayfair Bugle, The Queens Magazine, The Cornhill Magazine, Contemporary Review…“Yeah,” he said, “there were loads of magazines in late Victorian times, and some of them carried sensational stuff, about true crimes and all that. I bet there’s an account of the Little Tom murder there somewhere, though it might be tricky to find in the time available. It could give us a clearer sense of what happened and help us find the Source.” He threw the pen down. “I’ll get going shortly.”

“We’ve got big deliveries of iron and salt this morning,” Holly Munro said. “I’ll monitor that, and get your bags ready by early afternoon. You’ll want more candles.”

“Great,” Lockwood said. “You can help Holly, if you like, Lucy.”

“Oh, I’m sure Lucy doesn’t want to do that,” Holly said. “She’ll have something more important to do.”

Lockwood chewed a piece of waffle. “I’m not sure she has.”

The kettle boiled.

“Actually,” I said brightly, “I do. I think it would be much more useful if I went down to the Archives—and helped George.”

It wasn’t often that George and I went out together during the day (in fact I’d almost forgotten what he looked like when not surrounded by shadows, ghosts, or artificial light), and you could count the times I’d volunteered to help him at the National Newspaper Archives on the fingers of no hands. If George was surprised by my decision, however, he gave no sign of it. A few minutes later, he was strolling placidly through London at my side.

We walked south through the streets of Marylebone in the general direction of Regent Street. Though the Chelsea containment zone was a mile or two distant, the effects of the outbreak could be felt even here. There was the smell of burning in the air, and the city was quieter than usual. The cafés and restaurants of Marylebone High Street, which like all other commercial establishments closed at four thirty, were only ever busy at lunch; today their interiors were mostly gray and empty, with forlorn waiters sitting idly at tables. Trash bags lay uncollected on the sidewalks; litter blew across the street. More than once we saw orange DEPRAC tape blocking the entrances to buildings, and ghost-crosses daubed on windows: the signs of live hauntings, as yet undealt with by any of the agencies. They were busy elsewhere.

Outside a seedy Spiritualist Church on Wimpole Street, a scuffle was going on. Black-clothed followers of the Ghost Cult that worshipped inside were grappling with one of the local Neighborhood Protection leagues, who’d been trying to strew lavender on the church steps. Middle-aged men and women, gray-haired, outwardly respectable, shouted and screamed at one another, snatching at collars, twisting arms. As George and I drew near, they broke apart and stood in panting silence as we walked between them. When we’d passed, they closed up and began fighting again.

They were just adults. They were all equally clueless. When nightfall came, they’d all stop squabbling and scurry home in sync to bolt their doors.

“This city,” George said, “is going to hell in a handcart. Don’t you think so?”

For the first few blocks we hadn’t talked at all; I wasn’t in the mood for it. But air and exercise had partially roused me out of my gloom. I stamped my boot heels on the pavement. “I don’t even know what that means.”

“It means everyone’s getting frantic, and no one’s asking the right questions.”