A muscle above Callaway's lip twitches, even as she refuses to blink.

"Don't make me watch as you arrest her." My voice breaks. "Imagine if she were your best friend."

Callaway scowls at her notes and I go in for the kill.

"This won't work if you and I don't trust each other." Her eyes flicker and I know she's mine. "Please. Don't make me beg."

"Very well. I'm not thrilled, mind you. But we do appreciate your a.s.sistance." Frowning, she quickly pages through her notes. "All right, here is what we will do. You will meet Miss Frost at the tomb of Radclyffe Hall at a quarter past nine. You will hand over the bag she is expecting, with the items inside. The two of you will leave the cemetery together and then separate. One of my men will arrest Cecelia later, at Euston Station."

By the look on Callaway's narrow face I suspect she is lying. You are going to arrest Celia the moment we leave the cemetery. If not before. But now it's too late. I've said too much.

Callaway glances at her watch. "If you'd like to come back to the station, we've got a quiet room with a settee, a pillow, and some blankets. You can get a few hours' rest before your rendezvous."

"Thanks, but I'd rather stay here."

"Are you certain?" She eyes me suspiciously.

"Yes. I'm certain."

Callaway is about to say more when her cell phone rings. She reaches into her coat pocket, withdraws the phone, and pops it open in a single gesture.

"DC Callaway. What? No, I was just leaving. I hadn't heard." She holds the phone away from her face and covers it with her hand, anxiously leaning across the table.

"What is it?" I ask.

"Police in Birmingham have arrested seven members of a terrorist cell preparing to attack London." Her voice bristles with excitement. "They've caught the ringleader as well as the would-be bombers. The threat is over! They've been caught."

Chapter Seventeen.

Thursday 1:31 a.m.

I turn on the television and click through the channels but the story is so fresh it hasn't yet reached the media. From her colleague, Callaway gleans that the Birmingham terrorist cell was composed of homegrown hard-core fundamentalists, all born and raised in England, and that the tip that broke the whole case open came via a phone call from a member of the public, who reported that her neighbor's son was behaving "strangely."

"It's extraordinary," Callaway remarks, snapping closed her cell phone and shaking her head. "Young men willing to betray their own nation. Treachery at the deepest level."

As she speaks, I understand that not only is true treachery silent and interior, it can take many forms. "How could these young men do it?" I ask rhetorically. "And yet, some will question the woman who turned in her neighbor's son."

"That was an act of courage," Callaway insists, eyes flashing.

"I agree," I reply. "But there will be some who see it as an act of betrayal. It's all in how you look at things, I believe."

After we review the Highgate plan one final time, Callaway prepares to leave. I escort her downstairs, bidding good-bye at the front door. Then I quickly make my way back up the split staircase and enter Celia's flat for what I know will be the final time. Celia, too, will never again set foot inside this cramped and dreary little room that has been her home for more than two years. The whole life that was lived here-the relief center she founded and ran, the books and articles she wrote, the body that moved through this s.p.a.ce, the heart that felt the loss of a father, everything she thought and hoped and dreamed and cared about-all about to be dismantled. A life can seem so small, and never smaller than in its unraveling.

But now is not the time to be sentimental, not when I only have a few hours until I meet again with Celia. I know what Callaway said; the photos she showed me were overwhelming, but I have to be certain. I have to find out from Celia if what the police accuse her of is true. In the back of my mind, I suspect it might be. But I have to be sure.

I change clothes and pack quickly, filling my suitcase, my laptop bag, and my backpack, along with the red duffel bag from inside Celia's wardrobe, which I stuff with Celia's clean clothes, the cell phone, credit card, and 5000 cash. It has to look right. In case I do let them arrest her.

I grab whatever other useful items I can scavenge from the flat, which isn't much-scissors, Kleenex, a bar of soap, a couple of pens, and the box of black hair dye. I scour the kitchen for anything potentially edible but find only a can of Foster's beer, a small plastic-wrapped meat pie, and a Lyle's Golden Syrup cake.

I phone for a taxi and can just about handle the luggage with the backpack on my back, the laptop bag over one shoulder, and the duffel bag over the other, while I pull the suitcase with my one good hand. As I step into the hallway, the door to the flat slams closed behind me, rattling my bones like a stone rolled over the entrance to a tomb.

Once I maneuver myself and the luggage downstairs and out the front door, I find the cab waiting for me, parked at a provocative angle and with impatient puffs of exhaust belching from its tailpipe.

I am hurrying toward the curb when a timid voice behind me suddenly calls out, "Excuse me, miss?" I spin so quickly I nearly trip over my luggage. As I straighten, a tipsy figure teeter-totters out of the shadows and into the light. "They tell me you can help."

It is a girl, maybe fifteen, with long, straight dark hair parted down the middle, and dressed in a tiny denim miniskirt, bright red stilettos, and a too-tight white knit cardigan over a sheer yellow blouse open nearly to her waist. She must be freezing out here.

"I'm sorry," I say quickly, "my cab..."

She toddles closer, nearly twisting her ankle. "Please, miss. I can't go back." Her voice, Irish accented, quivers as she tries to be brave. "They say this place is safe. And that Cecelia Frost can help."

I set down the duffel bag and glance at my cab waiting across the street, worried he'll leave and I'll lose precious time phoning for another. "What's your name, child?" I ask with a sigh.

My question seems to surprise her. "N-Niamh," she sputters, and I know her name is definitely not Niamh. Mary or Margaret or Sinead-anything but Niamh. As she takes another step, I see the bruises along her jaw and red splotches decorating her neck. Her blouse is not open but torn, nearly in two. She only just got away. Next time she might not be so lucky.

"Niamh, Cecelia Frost isn't here. But I know someone who can help." Struggling to open my backpack with one hand, I slip Niamh three 20 notes and the business card that Sophie Jameson had given me at the hospital, then point to the cab across the street. "That cab is waiting. Tell him you're going to Hope House. The address is on the card. When you get there, ask for Sophie Jameson. She'll help you out."

Niamh stuffs the money into her back pocket and considers the card, tipping it toward the streetlight and squinting suspiciously. She opens her mouth to speak but I cut her off.

"Go on. Get out of here. Before I change my mind," I say brusquely. She nods in understanding and pockets the card, then bends, steps out of her stilettos, and runs delicately barefoot across the street, clutching the sharply angled shoes that bounce rapidly against her hip.

Whoever or whatever else Celia may be, she will never be any less than a hero to the people she helped, I think bleakly. I take out my cell phone but before I even punch the first number, a black cab turns the corner onto Rosslyn Hill and I hail him furiously, waving my good arm like a flag.

"So glad I caught you," I say as I open the door and pile the luggage into the backseat with no help from him, despite the cast on my arm. I glance into the front seat and see the meter ticking quickly. I've already wasted too much time.

"Where may I transport you, miss?" the cabbie asks as I struggle to close the door. I look up and see that he is young and handsome, possessing a cruel beauty made up of slim lips, smooth skin, and very round dark eyes. His cab is spotless and he is dressed surprisingly formally in a dress shirt and tie. I imagine he is Somali or Sudanese, some type of North African.

"Bayswater," I reply.

"Bayswater. Yes, miss. Where, precisely?"

"I'm not exactly sure. I'll let you know when we get there."

He nods solemnly. "As you wish, madame."

There is little traffic this time of night so it doesn't take long to reach Bayswater, a tacky-touristy area jam-packed with Indian takeaways and fast-food joints, souvenir shops, youth hostels, and cheap bed-and-breakfasts. It's the perfect place to blend in, to hide from Callaway and the police's prying eyes. A place where I can confront Celia and find out the truth.

I have the driver take me up and down the numerous side streets off the main thoroughfare. The streets, nearly deserted at this hour save for a few homeless people and a handful of stumbling drunks, are lined with deceptively elegant-looking town houses, three or four stories high, featuring cream-colored brick, wrought-iron railings, and tall, porticoed columns. Upon closer inspection, though, these seemingly grand buildings are in fact ramshackle and unkempt, with peeling paint, cracked windows, and signs advertising Full English Breakfast and Double Rm 100 Nt.

As we drive I can't help but think about the girl, Niamh-whose-name-is-not-Niamh, wondering if she's reached Hope House yet, if Sophie Jameson is this very moment showing her the army cot where she will sleep, and handing her a scratchy hand towel and a brand-new, unwrapped bar of soap that Niamh will clutch like a rosary, pressing it to her face and inhaling deeply the fresh clean scent of lavender.

Even if Niamh is safe, there are so many like her still out here, lurking in the shadows, ducking into corners, huddled at bus stops, frightened and alone. An army of missing girls, invisible women, and discarded, throwaway children. More than anything I want to know that my son is all right. Gone, perhaps, but not lost; bundled up somewhere, in a place beyond my reach. Safe and at peace, cradled in the arms of a great someone.

I have the driver stop in front of the Greenland House Hotel, a white three-story town house that displays both a Union Jack and an Australian flag in its front window. It's a modest-looking establishment, the second from the end in a row of run-down lodgings. I ask the driver to wait while I check to see if I can book a room for the night. He nods solemnly, half closing his eyes.

The only available room is located in the damp, foul-smelling bas.e.m.e.nt, where the floor is concrete and the scant light comes from a bare bulb swinging on a chain overhead. The room itself, cramped and dingy, has just one double bed. At least the bathroom, although filthy and ringed with mold, is en suite. I tell the desk clerk I'll take the room: one night, two guests. I have no choice-I'm running out of time and I have to find Celia.

I deposit my luggage in the room, struggle to close and lock the warped wooden door, then return to the waiting cab with nothing but my backpack over my shoulder.

"Now to Gospel Oak," I say, breathless from rushing up the stairs. "Gospel Oak Primary School, to be precise."

Suddenly the driver seems more interested and his dark eyes widen. "Do you seek a companion for the evening?" he asks.

"You could say that," I reply, settling back as he peels away from the curb.

I don't have time to chase all over London looking for Celia, so I have to stake everything on my belief that Gospel Oak Primary School is where she would spend what she believes to be her final night in England. When we shared our flat in Clapham, Celia would often spend a full Sunday afternoon at the primary school, sitting on the playground swings and brooding. The place had a special resonance for her because it was within sight of where her mother had died. When Celia was a toddler, Maggie, then age forty-two and suffering from terminal brain cancer, threw herself in front of a train at the Gospel Oak station, just a few minutes' walk from the school and playground.

Celia made this regular pilgrimage not to feel close to her mother, the dead being for Celia only and always dead, but to contemplate Maggie's final act while imagining the last things her mother saw, heard, and felt before she died. For Celia this became a way of facing the loss and abandonment, by staring, unblinking, into the abyss of her own grief.

The school is located on Mansfield Road, a quiet residential street near the southeastern corner of Hampstead Heath. The school itself is a nondescript 1970s-looking two-story building, long and narrow, with a flat roof and rows of small square windows. I have the driver wait in front of the school, promising I'll be back in twenty or thirty minutes. When he looks skeptical, I give him a 50 note, a deposit for the 78 I owe him so far.

The large, modern playground is in the back, behind the school buildings, and well appointed with basketball hoops, soccer nets, and monkey bars. The grounds, as I enter, appear to be deserted, and I am struck by the hushed, eerie, otherworldly quality that a child's play area can take on at night. It is as if under cover of darkness the ghosts of children long since gone rise up again to mingle and dance, while the echo of their lost laughter moves across an invisible threshold, parting the damp blades of gra.s.s as it pa.s.ses.

Celia is not where I expect to find her, on the canvas swings opposite the red metal slide. But in the distance, on the playground's periphery, I see a lone figure, smoking, huddled at the end of a wooden bench, illuminated by a muted pool of sulfur-colored light spilling from a streetlamp overhead. Blue-gray plumes of smoke emerge from the figure's mouth in a steady rhythm, in and out, briefly circling the head like a ghostly garland before retreating, dissolving into the blankness of night. Celia. It has to be.

I approach, walking quickly, and as I draw closer she looks up with a start. When I am within thirty feet she withdraws a knife from the pocket of her denim jacket, the glint of the silver blade catching and reflecting the light. When she realizes it is me, she smiles, her small teeth flashing brightly in the dark.

"We weren't supposed to meet until quarter past nine," she calls out, sliding the knife back into her pocket.

"I couldn't wait that long," I reply.

"How did you know I'd be here?" She squints behind her cigarette, shivering from the cold.

"A lucky guess?"

"Right." She scoots over and I sit down on the bench beside her with my right side pressed against her left. For a moment I revel in the familiar feel of her thin body, brittled by exhaustion, and absorb the full force of a life that a few hours ago I was certain no longer existed. All my fears, questions, and doubts disappear and this is Cecelia Frost, my Celia, the Celia I've known since I was thirteen. She couldn't be guilty of the terrible things Callaway claimed. So why don't I just ask her?

"You're freezing." I put my arm around her shoulders and rub her sinewy bicep. Her clothing is damp and she shivers. "You aren't dressed for this weather. Were you planning to stay here all night?"

"No, but for as long as I could manage it," she admits, dropping her chin to her chest and withdrawing for warmth. "I try never to stay in one place more than a few hours. I'm still not certain who may be following me."

She offers me her nearly finished cigarette but I decline, shaking my head. She shrugs, takes a final puff, then tosses it to the ground and stubs it out. We are both quiet for several moments, listening intently to the m.u.f.fled dark, waiting for shape or sound to emerge and a.s.sert itself. "This place has changed greatly," Celia finally says, surveying the school and the playground. "Back in the seventies and eighties, they had little prefabs scattered about back here, to handle the overflow of students."

I try to visualize the scene. "That must have looked weird," I offer.

"Indeed." She blows on her palms, then rubs her hands for warmth. "This place was bombed during the war, you know."

"Really? The Germans bombed a grade school?"

Celia nods. "Yes. Although it is believed that the Luftwaffe were actually aiming for the railway station and hit the school by mistake."

"Oh." I stare out at the multicolored circles, squares, and other shapes that divide up the playground's smooth black surface, delineations for games I will probably never witness or understand. "I've always loved the history here," I whisper. "London. The UK. Europe. It's as if every inch of s.p.a.ce contains several generations of stories."

"Yes. And my own history is here too," Celia adds softly. "Mum died just over the road." She gestures with the shrug of one shoulder, not bothering to turn around.

I nod. "Yes, I remember you telling me. Gospel Oak railway station."

Celia spreads her fingers, indicating the width of the playground, from the school buildings to the street. "And this is where they found me."

"They found you?" I ask, confused.

She nods. "I was here."

"What do you mean?" My skin p.r.i.c.kles. "You were here when she died?"

"Yes. I was here on the playground while Mum was busy, off killing herself."

Chapter Eighteen.

Thursday 3:51 a.m.

I shudder at the image of the toddler Celia, orphaned on the swings, waiting hopefully for the mother who will never return.

"I think, originally, she intended for me to die too." Celia shivers, plunging her hands into her pockets. "I believe she planned to throw herself in front of the train with me in her arms. But something changed her mind."

In my head an already bleak scene grows steadily darker and I feel the need to defend a long-dead woman I never met. "Your mother was terminally ill," I propose. "Maybe she thought she couldn't bear to leave you behind. But when she got here, she felt differently."

Celia bristles. "My mother was not sentimental."

"But I am?"

"No. You're not sentimental, you're just"-she lowers her voice-"American." She pauses. "You know what I mean."

Ignoring the insult, I continue. "I believe your mother wanted you to live. That's what any woman would hope for, that her child might survive and go on without her."

Celia pokes a pebble with her toe, coaxing it to turn over. "I remember I was wearing my favorite coat, white wool with a fur collar. Mum sat me on the swing with an ice cream, then shoved a sc.r.a.p of paper in my pocket. As she walked away, she turned and waved. When I waved back, I dropped my ice cream and started to cry. I looked up and she was gone."

Celia shakes her head. "There must have been a great commotion at the station, but I heard nothing. They found me an hour later, still waiting. Inside my pocket was the sc.r.a.p of paper with my name, my father's name, our address, and phone number." Celia's voice is soft but steady, devoid of emotion.

"I found the little white coat neatly folded in a box beneath the bed when I cleared out Dad's things after he died. So unlike him to keep it all these years. The sc.r.a.p of paper was still in the pocket-someone must have shoved it back in there after ringing Dad."