Her hands were hidden in an oversized white ermine muff, and her breath was puffs of steam whisked away on the breeze as she peered at the variously shaped dark doorways she passed on either side. Finally she halted, and for nearly a minute just stared at a brass plaque beside the door of an otherwise unremarkable house:

The plaque read: JOHN CRAWFORD, M.R.C.V.S. SURGERY FROM 9 TO 11 O'CLOCK.

The knocker was a wrought-iron cat's head, hinged at the top.

A bigger plume of steam blew away from under her bonnet, and then she stepped to the door and carefully freed one gloved hand to give the knocker two sharp clanks.

"In sunshine or in sha-adow," she sang softly to herself; then she smiled and touched the ermine muff. "And kneel and say an ave there for me."

She heard steps from inside, and a curtain twitched in the frosted window at her left, and then a bolt rattled and the door swung inward.

The man who had opened the door blinked out at her without recognition. "Is it an emergency?" he asked. "The surgery isn't open for hours yet."

He wore a brown sack-coat with an outmoded plaid shawl over his shoulders, and she noted that his beard was still dark brown.

"Come in," he added, stepping aside.

She walked past him into the hallway's warm smells of bacon and garlic and tobacco as he closed the door behind her and asked, "Can I take your coat?"

She laid the muff on a table and pulled off her muddy boots and her gloves; then she shrugged out of her blue velveteen coat, and as she handed it to him, the muff on the table squeaked and chirped.

He paused, looking from it to her, and raised his eyebrows.

"Er ... do you," she asked with a tight smile, "minister to birds?"

"I really only ever go as small as chickens, and that sounded like a songbird. My main customers are cab horses, and I do pro bono publico work for stray cats." He smiled. "But I suppose I can advise, if you'll bring the patient in." He waved toward an open doorway, and the woman retrieved the muff and stepped through into a parlor with framed hunting prints on the green-papered walls. The ivory-colored curtains over the front windows had probably been white originally.

A cold fireplace gaped below a marble mantelpiece that was still hung with tinsel and wilted holly. A dozen wooden chairs were ranked closely along two of the walls, and a long couch hid the sills of the street-side windows. Half a dozen cats were sprawled on the couch and the low table.

"Do sit," said Crawford. "I'll fetch in some tea."

He disappeared through an inner door, and the woman pushed several of the cats off the couch onto the carpet - one had only three legs, and another appeared to have no eyes, though they all scampered away energetically - and sat down on the cleared cushion. She carefully slid a small cylindrical birdcage no bigger than a pint-pot out of the ermine muff and set it upright on the table. The tiny brown bird within peered around the room, paying no evident attention to the retreating cats.

This room was chillier than the entry hall, and, in addition to the apparently constant whiff of garlic, smelled of dogs and spirits of camphor. A framed notice between two pictures of leaping horses listed prices of various operations and remedies.

Crawford came pushing back in through the door carrying a tray, and as he set it on the table he said, "And what ails your bird, Miss...?"

"McKee," she said. "Adelaide McKee." He had poured steaming tea into a cup, and she accepted it with a nod, ignoring the pots of sugar and milk. "Who is Mister C.V.S.? I didn't notice the sign the last time I was here."

"Mister...? Oh! That's me, I suppose. The whole thing stands for Member of the Royal College of Veterinary Surgeons." He pulled up one of the wooden chairs and sat down across the table from her. "You've been here before? Was it another case of bird malaise?"

"I gave you a different name then." She untied the strings of her bonnet and pulled it off, shaking out her shoulder-length chestnut curls. "And it was seven years ago." She glanced around the room. "Frankly, I'm surprised to find you still here."

Crawford had poured himself a cup too, and started to raise it, but now he clanked it back down onto the saucer. His face was chilly with a sudden dew of sweat, and two full seconds later his ribs and the backs of his hands tingled with remembered fright and enormous present embarrassment.

HE HAD STILL BEEN drunk most of the time in that summer of 1855, and on many nights memories of his wife and two sons had kept him from sleeping; on those nights he had sat up drinking and trying to lose himself in cheap novels or, giving up on that, gone for long walks along the banks of the Thames.

And on one such rainy summer midnight, he had found himself drawn toward the lights along the south shore of the river - but when he had paid his ha'penny at the Strand-side turnstile of Waterloo Bridge and walked out as far as a recessed stone seat above the third of the bridge's nine arches over the river, he stopped there with such deliberateness that he wondered for a moment if he had had some now-forgotten purpose in coming out here.

There were no lamps on the bridge, and he had been able dimly to see the silhouette of St. Paul's Cathedral a mile away to the east, and strings of yellow and orange lights on the south shore flickering through the veils of rain. Occasional patches of moonlight shone on the rain-dulled water below him.

His wife and sons had died on the Thames two years earlier, in a boating accident, and he wondered, with some alarm, if his purpose in coming out here had been to throw himself into that same water, perhaps maudlinly inspired by Thomas Hood's poem about a prostitute who had committed suicide off this bridge.

His wife's name had been Veronica. His sons had been Girard and Richard. He stood there for several minutes, while rain washed away the tears on his cheeks, and told himself, They're gone. They're gone.

Over the hiss of the rain and the constant hoarse whisper of the river shifting around the bridge pilings below, he became aware of a metronomic clinking getting louder. A woman was walking toward him from the Blackfriars side of the bridge, and she evidently had metal pattens on her shoes to protect them from puddles. The round bulge at the top of her silhouette was certainly an umbrella. Embarrassed at being caught weeping, even though it would not be evident, Crawford straightened and wearily got ready to lift his hat as she passed him.

His hand was on the brim of his bowler hat, and the silhouette of the umbrella became wider as she presumably glanced toward him -

- And then for a frozen instant it seemed that a piece of the umbrella broke free and hung in the night air, swelling rapidly in size -

But it was something rushing down at the two of them out of the charcoal sky, something alive and churning and savage, and at the sudden roaring of it the woman glanced up and then leaped backward, colliding with Crawford and spinning him half around.

The harsh bass noise of the thing was like a locomotive about to hit them, compressing the air, and a sharp machine-oil smell like ozone was harsh in Crawford's nostrils. In a convulsion of total panic, he seized the woman around the waist, boosted her right over the stone railing, and pitched her away from the bridge - she had been too breathless even to scream - and in the same motion he slapped one boot onto the wet stone bench and sprang over the railing after her.

Then he was plummeting through yards and yards of empty rushing air, and he crashed into the cold water before he had thought to take a breath; he might even have been screaming.

When he thrashed back up to the surface, gasping, he could see the woman flailing in the water near him, her billowing crinoline at once keeping her afloat and impeding her efforts to swim, but before struggling out of his heavy coat and starting through the water toward her, he threw a fearful glance up at the bridge high overhead. For a moment there might have been a flexing, spiky bulk visible at the railing, but if so, it had withdrawn by the time he had blinked water out of his eyes for a clearer look.

He swam to the struggling woman and grasped her upper arm, then began kicking through the frigid salt water toward the shore. The current swept them east, past the arches and water gates of Somerset House, and he managed to slant in at the steps below Temple Place. The woman had also lost or shed her jacket in the river, and both of them were shaking as they climbed on their hands and knees up the steps to the narrow river-side pavement.

Looking back fearfully, Crawford couldn't make out the bridge at all in the darkness. From very far away he thought he caught a slow bass thrumming under the percussion of the storm.

His hand slapped his waistcoat pocket, but the little jar he sometimes remembered to carry wasn't there.

Cold rain clattered around him, and river water dripped from his beard. "What," he choked, "the bloody hell - was - "

She put her cold palm across his mouth so quickly that it was almost a slap, and water flew from her stringy wet hair. "Don't ... give words," she panted. "Don't ... draw, attract." She lowered her hand to grip the edge of the pavement. "We need to get indoors. Walls, a roof."

He was panting too. "I - live near here. Five-minute walk."

She nodded. "Good - but first - " She rolled over and sat up, apparently to untie one of her shoes. A moment later she handed him the metal frame that had been strapped to the bottom of it.

"Strap that over the sole of one of your boots," she said. "Quickly - even with this change in our silhouettes, we've got to be inside before the rain washes the salty river water off us."

He didn't argue. He was still breathing rapidly, and when his shaking fingers discovered that the straps wouldn't fit over the instep of his boot, he impatiently pulled his sopping scarf from around his neck and tore it lengthwise in half. He used the narrower strip to tie the metal sole onto his left boot, with a big wet knot over his instep.

The woman had got to her feet. "Come on," she whispered. "You go, lead the way - I'll follow about twenty feet behind you. We've got to stop our auras overlapping."

"Auras." Crawford stood up unsteadily on the wobbly metal sole. "We're," he said to her, "safe? For now?"

"Safe?" The streetlamps of Arundel Street ahead of them threw enough light for him to see her wondering frown. "Go. I'll follow."

The two of them weren't much wetter than the few other pedestrians they passed, as first Crawford and then the woman crossed the muddy gravel lanes of the Strand, and the one cabbie that reined in his horse for a moment just shrugged and sped up again when Crawford waved him off. The unsynchronized crunch of the shared pair of pattens sounded like the footsteps of a drunk repeatedly attempting and then abandoning a difficult dance step.

When he had walked quickly down the narrow lane that was Wych Street to his own front door, he looked back as he dug the key from his pocket. The woman had stepped in under the overhanging upper floor of an old house a dozen yards behind him.

His hands were shaking but he was careful to twist the bolt back as quietly as possible, and then he paused to reach down and push the knotted strip of scarf forward off his boot; ordinarily he would have stepped straight into the parlor and yanked the bell-pull to summon Mrs. Middleditch from her little top-floor bedroom, but tonight he wanted to recover from whatever it was that he had just participated in, without extra witnesses.

He swung the door open, lifting its weight against the hinges, and stepped into the unlit entry hall. He waited until the woman had hurried in past him, then shut the door and rotated the bolt knob. The rattle of the rain on gravel was shut out, and the only sound was panting breath and the dripping of water on the waxed wooden floor.

The woman was carrying her shoes now, and laid them carefully on the hall table.

"This way," he whispered, and stepped into the parlor.

The fire in the grate was just glowing coals, but he propped a couple of fresh logs in there and tucked some crumpled newspapers under them, and after he had fetched a decanter and two glasses, he and his unknown companion sat on the carpet in front of the reviving fire and took the first, restorative gulps of whisky. The warm liquor burned its way down his throat and began to loosen his tensed muscles.

The fire was flickering brightly now, and he pressed water from his hair and beard and then held his chilled palms out toward the heat. He exhaled, and for the first time looked squarely at his companion. She was younger than he had assumed, perhaps twenty. She had pushed her dark hair back from her forehead, and her face was pale and narrow.

The windows rattled, and the woman's head whipped around - the noise wasn't repeated, and after a few seconds, she slowly turned back toward the fire.

"Wind funnels down this street," Crawford said. That was true, and probably it had been the wind. But he sighed and glanced at the clock on the mantel and saw that it was well after one in the morning. "I have a guest room, here, with a bath," he said. "My housekeeper can show you where it is."

She nodded. "Thank you."

"What," he began at last, giving her time to stop him; but the wide dark eyes simply held his, so he went on: "was that?"

Her abrupt laugh was quiet but jarring. "The gentleman wants to know what it was," she said. "This isn't your first drink of the evening, is it? Let's see, it appeared when you and I were close enough that we could have touched each other, and you knew to get us into the river, and - and your parlor reeks of garlic! What do you, now that you can ponder it, imagine that it was?"

Crawford drained his glass and refilled it. "The garlic," he said weakly, "is a disinfectant. Prevents mortification. I'm a veterinary surgeon."

"A veterinary surgeon." She looked around at the tidy room by the flickering firelight: the framed prints, the old-fashioned vine-patterned wallpaper, the street-side curtains. "Smells like you treat a lot of mortified horses right in here."