"No. I saw her from a distance. In the crowd in Trafalgar Square the night before VE-Day. She was standing next to one of the lions. The one whose nose had been knocked off in the Blitz."

"You were in Trafalgar Square on VE-Day," Mike said. "When did you come through?"

Polly thought rapidly. They'd never believe she'd only been there for the two days of the victory celebration. "April eighth," she said. "I was there to observe the winding down of the war during its last few weeks. I posed as a Wren working as a typist in the War Office."

"A typist," Eileen said.

"Yes."

"April eighth," Mike said. "That gives us four years-"

"Four years and five months," Eileen said.

"Right," Mike said. "Nearly four and a half years. And when I was talking about increased slippage, I meant a few months, not years. We'll be out of here long before your deadline, Polly."

"Which is what?" Eileen asked.

Mike looked at Eileen in surprise. "She just told us. She said she came through April eighth-"

"She's lying. That isn't her deadline."

There was a silence, and then Mike said, "Is she right, Polly? Are you lying?"

"Yes," Eileen answered for her. "When I told her about one of the historian's drops to the Reign of Terror and the storming of the Bastille being switched, she went absolutely white, and they were only four years and two months apart."

And I'm obviously not as good an actress as Sir Godfrey's always telling me I am, Polly thought, cursing herself for not having said she'd gone through earlier than April. "It was Pearl Harbor I was worried about, not-"

"Wait. Stop," Mike said. "Pearl Harbor? The storming of the Bastille? I have no idea what either of you are talking about. Explain."

Polly said, "After you and I talked about an increase in slippage possibly being the problem, it occurred to me that Mr. Dunworthy might have been putting all the assignments in chronological order."

"Chronological? You're right. He did put all mine in chronological order. That's why you asked me about the order of my drops when you called."

"Yes." Polly explained about Eileen's notes and her concluding that the increase might be much longer than a couple of months. "And I was frightened. Some of the worst raids of the Blitz will be after the first of the year, and we don't even know when and where they are. And I'm not even certain our boardinghouses are safe from January on." Which had the advantage of being true.

And let's hope it convinces them, Polly thought.

"That isn't the only reason," Eileen said grimly. "Ask her why, if she was a typist in the War Office, she knows all about driving an ambulance. When I told her I had to learn to drive that day we talked to you in Oxford, Mike, she offered to teach me. On a Daimler, because that was what all the ambulances were."

"I'd learned that from my prep for the Blitz," Polly said. "I studied the Civil Defence-"

"And ask her why she turned and ran from a group of FANYs we saw on the platform in Holborn. She knew them from her assignment, that's why. She never tried to avoid walking past Wrens."

And all the time I was afraid she was fretting over Mike, she was actually playing detective like a character in one of her Agatha Christies, Polly thought. I underestimated her. But she can't have figured it all out.

"And ask her where she went when she said she was going to St. Paul's to meet the retrieval team." She turned on Polly. "When I got to the National Gallery, it was pouring rain and the concert wasn't till one, so I thought I'd come to St. Paul's and meet you. But you weren't there."

"Yes, I was. We must just have missed each other. St. Paul's is huge, and there are so many chapels and bays-"

"I saw you come in. I saw you buy that guidebook and spill pennies all over the floor. She was drenched," Eileen said to Mike, "like she'd been out in the rain all morning. And don't bother pretending you were up in the Whispering Gallery, Polly. It's closed. And the sermon wasn't 'Seek and Ye Shall Find.' It was 'The Lost Sheep.' You must have picked up an order of service for the early mass by mistake. Where were you?"

At least this was a question she could answer. "I was at Hampstead Heath. That was where my drop for VE-Day was." She looked at Mike. "When you sent that message from Bletchley about older drops, I went to see if they might have opened mine to use for an emergency exit. And I couldn't tell you, Eileen, because I didn't want you to find out I'd been here before."

"Is that the truth?" Eileen said.

"Yes." And please, please, let that be all you know.

"You swear?" Eileen said.

"Yes."

"Then why didn't you know about the bomb at St. Paul's, but you knew all about V-1s and V-2s?" She turned back to Mike. "She knew the exact date the V-1 attacks began. Don't you see? She was the historian who did the rocket assignment. She drove an ambulance in Bethnal Green. Didn't you, Polly? That's why you were so upset when I told you we had to go there to get me a new identity card. Because you were afraid someone in Bethnal Green would recognize you. You were attached to the ambulance unit there, weren't you?"

"No," Polly said. "To the ambulance unit in Dulwich."

Wars are not won by evacuations.

-WINSTON CHURCHILL,

SPEAKING OF DUNKIRK.

Oxford-April 2060 THE SHIMMER FLARED. "COLIN'S NOT TO COME THROUGH AFTER me," Dunworthy said again, though the shimmer was too bright-Badri would never be able to hear him. But he tried nonetheless. "He's not to come. No matter what excuse he gives you."

It was too late. He was already through. And definitely in St. Paul's, though he couldn't see a thing. His words echoed and then died away into the hush of a high, open, vaulted space. He'd have recognized it anywhere, just as he'd have recognized the distinctive chill. It had always felt like the dead of winter in St. Paul's. He peered into the solid darkness, waiting for his eyes to adjust. It clearly wasn't four A.M. Or if it was, there'd been locational slippage, and he'd come through in the Crypt instead of the north transept.

No, this couldn't be the Crypt. The fire watch had their headquarters down there, and there'd be lights. But he might be inside one of the staircases. No, the sound wasn't that of an enclosed space. He wasn't willing to take chances, though. He'd come through on a flight of stairs one time early in his career and nearly pitched off it and killed himself. He slid one foot forward and then the other, feeling for an edge.

He was on a flat surface. A stone floor, so this had to be on the main floor of the cathedral, which meant it was far earlier than four A.M. But even if it were midnight, there should be some light. The raids in the early morning hours of the tenth had been less than half a mile from here, and some of the docks had still been burning from the first two nights' raids. And there should be searchlights.

And noise. But he couldn't hear anything-no clatter of incendiaries, the bane of St. Paul's. No muffled thud of bombs. No droning of planes overhead. No sound at all, except the distinctive hush. What if Linna had got the coordinates wrong in her haste, and this wasn't 1940? Or what if Dr. Ishiwaka had been right?

But when Dunworthy put his hand out, it connected with canvas and a yielding weight, which could only be a sandbag. He patted around it. More sandbags, and when he felt his way around them to the wall and along it, he came to a carved wooden doorway. The north doors. Which meant he was exactly where he was supposed to be, and the sandbags meant he was in the general vicinity of when.

There should be two steps leading down to the doors. He felt his way carefully down and tried to open them. They were locked. Locked? John Bartholomew had said they kept the cathedral unlocked. But he wasn't here yet. He wouldn't arrive till the twentieth, and perhaps St. Paul's hadn't unlocked the doors till later, after the necessity of getting fire hoses in became apparent.

It should have been apparent from the beginning, Dunworthy thought irritably, groping his way back up the steps. Now he'd have to go all the way down the nave to the west doors. Which would take him an hour at this rate.

Perhaps he should sit down and wait for it to grow light enough to see, but it was too cold. His teeth were already chattering. And the longer he waited, the more likely he was to run into the fire watch and have to explain what he was doing here. He could always tell them he'd come in looking for shelter when the sirens went and had fallen asleep, but if he and Polly were seen when he brought her back here, there could be complications. Worse, they might decide they needed to make a sweep of the cathedral every night. Or lock the west doors.

He needed to get out now, before anyone saw him. And if he was lucky, and it was as early as the darkness and the lack of raids suggested, the trains would still be running, and he could make it to Notting Hill Gate before they stopped. He could spend the night searching that station, search High Street Kensington and the others on the list as soon as the trains began again in the morning, and find Polly before nightfall and have her back in Oxford before breakfast. And he could stop worrying over what might happen to her if Dr. Ishiwaka was right.

He patted his way cautiously back along the wall, around the sandbags. Wall, more sandbags, pillar ...

His foot hit something metal, and it fell over with a terrific, echoing clatter. He dived to silence whatever it was, and his hand came down in a bucket of freezing water and nearly knocked it over. He felt frantically for the thing he'd banged into.

A stirrup pump. He could tell by the metal handle, the rubber hose. He straightened, clutching the pump in both hands and peering anxiously into the blackness, listening for running footsteps or a shouted "What was that?"

Neither came, which meant the entire fire watch was still up on the roofs, thank heavens, and if he could just reach the nave with its high windows, there should be a bit more light and he'd be able to see where he was going.

There wasn't any more light. The wall he'd been patting his way along ended and the quality of the hush changed, so that he could tell he was in a wider, higher space, but it was still pitch-black. Bartholomew had said they'd kept a small light burning on the altar at night for the fire watch to orient itself by, but when he looked toward where the choir and the altar should be, there was nothing but a black blankness.

And I will have a few things to say to Mr. Bartholomew on the accuracy of his historical reporting when I return to Oxford, he thought, feeling for the angled and fluted pillars that formed the corner of the wall. He didn't dare go out into the middle of the nave. It was full of wooden folding chairs to crash into. He'd best keep to the north aisle.

He felt along the aisle's wall, one hand on the cold stone and the other hand in front of him, attempting to remember what lay along it. Lord Leighton's statue, he thought, and promptly stumbled over it, the sandbags breaking his fall.

I'm too old for this, he thought, getting to his feet again and working his way past it, past an alcove, a rectangular pillar, another alcove. And another bucket, this one full of sand-which he nearly broke his toe against but, thankfully, did not knock over.

Colin was right, I should have brought a pocket torch, he thought, feeling his way around another pillar. And up against what was unmistakably a brick wall.

There aren't any brick walls in St. Paul's, he thought. Could I be somewhere else altogether? Then he realized what it was. The Wellington Monument, which they'd bricked up because it was too large to move. He worked his way quickly along its face to the next pillar. After this there should be only the All Souls' Chapel and then St. Dunstan's Chapel before he reached- A door slammed somewhere behind him, and footsteps hurried down the nave toward him. Dunworthy ducked behind the pillar, hoping he was out of sight. "I'm certain I heard something," a man's voice said.

"An incendiary?" a second voice asked.

No, you heard me crashing about, Dunworthy thought. They were obviously members of the fire watch.

A pocket torch flashed briefly. Dunworthy shrank further behind the pillar. "I don't know," the first man said. "It might have been a DA."

A delayed-action bomb, Dunworthy thought.

"Bloody hell, that's all we need," the second one said. And bloody hell was right. They'd search the entire cathedral.

"It sounded like it was in the nave," the first one said, and Dunworthy braced himself, wondering what sort of tale he could concoct to explain his presence. But when the torch flashed again, it was over toward the south aisle, and their footsteps grew softer as they moved away from him.

Dunworthy stayed where he was, trying to hear what they were saying, but he only caught snatches. "... have been on the south chancel roof? ... likely put it out ..."

They must have decided it was an incendiary after all. They were all the way to the west end of the nave. He caught, "... over for tonight ..." and something that sounded like "Coventry," though that was unlikely. He didn't think Coventry had been bombed before the fourteenth of November.

"... north aisle?" one of them said, and Dunworthy looked back toward the transept, wondering if he should retreat there.

"No ... check the gallery first." There was a brief flash of light, and Dunworthy heard a clank of metal and footsteps ascending.

They're going up Wren's Geometrical Staircase, he thought, and took advantage of the covering sound of their footsteps to walk quickly along the aisle, his hand on the wall for guidance. Pillar, pillar, iron grille. That was St. Dunstan's Chapel. The vestibule and the door should be just beyond.

"... find anything?" he heard from somewhere above him. He ducked for cover moments before the pocket torch's light flared down.

"Here it is!" one of them shouted; it must have been the first one because he said triumphantly, "I told you I heard something. It's an incendiary. Fetch a stirrup pump."

Dunworthy heard the second one racket along the gallery overhead. He felt his way quickly to the door, opened it, and slipped out to the porch and the steps.

And into pouring rain. Which explains why it's so dark, he thought, ducking back under the porch's roof. It was nearly as dark out here as inside. If he hadn't known there was a pillared porch and then steps, he couldn't have found his way down to the courtyard.

He squinted across it. He could only just make out the dark outlines of the buildings opposite. The rain also explained the absence of searchlights and of bombers droning overhead-the Luftwaffe would have had to call off the raids when this started. And it explained there not being any fires. The rain would have put all of them-except for the incendiary that had come through the gallery's roof-out.

Dunworthy glanced up at the bell tower to see if they were up there and then splashed down the steps. To reach the tube station, he needed to find Paternoster Row and then Newgate.

And watch where he was going, though that was almost impossible to do in this downpour. It beat against him icily, more like sleet than rain. He hunched forward, ducking his head against its onslaught.

At any rate, no one else will be mad enough to be out in this, he thought, pulling the collar of his tweed jacket up tightly round his neck, but he was wrong. There were two figures walking straight toward him. Members of the fire watch? Or civilians on the way home from the tube station? Or an ARP warden who would demand to know what he was doing out on the streets and hustle him off to a surface shelter?

He splashed quickly across the road and down the narrow lane to his left. It was scarcely six feet across, and what little light he'd had to see by was utterly shut out by the buildings on either side. It was as dark as it had been inside the cathedral. He had to return to feeling his way, and it took him forever to reach Paternoster Row.

If it was Paternoster Row. It didn't look like it. It was no wider than the lane and was lined with ramshackle houses instead of publishers' offices and book warehouses. It also seemed to have a deeper descent than it should, though that might be a trick of the darkness.

Its abrupt end in a courtyard wasn't. He must have missed Paternoster Row in the dark. He retraced his way back to the lane and up the way he'd come.

But it wasn't the same lane. This one ended in a wooden stable. You're lost, he thought furiously. You should have known better than to wander about in the dark in the City.

There was no worse place in London-or history-to be lost. The area surrounding St. Paul's had been a rabbit warren of confusing lanes and mazelike passages, most of them leading nowhere. He could wander in here forever and never find his way out. And the rain was coming down harder than ever.

"I am positively too old for this," he muttered, craning his neck to catch a glimpse of St. Paul's, but the buildings were too tall, and there was nothing to orient himself by. He no longer even knew which direction the cathedral lay in.

Yes, you do, he thought. You know exactly where it is. On top of Ludgate Hill. All you need to do is climb up the hill. But that was easier said than done. There were no streets going up. They all led inexorably downhill, away from St. Paul's and from the tube station. But if he continued downhill, he'd eventually come to Blackfriars, or, if he was too far east, Cannon Street. Either tube station would have trains which could take him to the station where Polly was. He turned down a lane and then another.

After two more turns and another cul-de-sac, he came to a broader street. Old Bailey? If so, Blackfriars lay at the foot of it. It was finally growing light, at least enough to see that the street was lined with shops, and the shops had awnings. He splashed across the street, eager to get even partially out of the rain.

Nearly all the shop windows were boarded up. Only the second from the corner still had glass in it, and as he drew nearer, he saw it was boarded up as well. What he'd thought was glass was actually a reflection from a garland of silver-paper letters nailed to the wood. They spelled out Happy Christmas.

It can't be Christmas, he thought. If it was, there'd have been a Christmas tree in the nave and another outside in the porch. John Bartholomew had talked about its having been repeatedly knocked over by blast.

But the trees could very well have been there. He wouldn't have seen them in the darkness.

But if it's Christmas, he thought, that means there's been nearly four months' slippage, and that's impossible. The increase was only two days. But he knew it was true. That was why it was so cold. And so dark. The net had sent him through at four A.M., but in December four A.M. would be pitch-black.

"Ascertain your temporal location immediately upon arrival." Wasn't that what he was always enjoining his students to do? He should have realized it couldn't be September tenth when there weren't any fires. They hadn't got the ones on the docks out for nearly a week.

But he'd ignored the clues, and now he'd have to climb all the way back up that hill in the rain. Because Polly wasn't here. Her assignment had ended the twenty-second of October. She'd been safely back in Oxford for at least a month and a half, and this had been an exercise in futility.

Except that now he had the proof he'd been looking for that the slippage was beginning to spike. He had to return to St. Paul's immediately, go back through to Oxford, and tell Badri to pull all the historians out. He started back up the hill, looking for a taxi, but the streets were completely deserted.

No, wait, there was one, in the darkness at the end of a side lane. He stepped into the lane and hailed it.

It had seen him. It pulled out and began to move toward him, and thank God Colin had insisted on his bringing money. Dunworthy pulled out his papers and shuffled through them, looking for the five-pound notes, and then looked up again.