"Be quiet," said Will, "just be quiet. Don't disturb me."

It was just after Lyra had been taken, just after Will had come down from the mountaintop, just after the witch had killed his father. Will lit the little tin lantern he'd taken from his father's pack, using the dry matches that he'd found with it, and crouched in the lee of the rock to open Lyra's rucksack.

He felt inside with his good hand and found the heavy velvet-wrapped alethiometer. It glittered in the lantern light, and he held it out to the two shapes that stood beside him, the shapes who called themselves angels.

"Can you read this?" he said.

"No," said a voice. "Come with us. You must come. Come now to Lord Asriel."

"Who made you follow my father? You said he didn't know you were following him. But he did," Will said fiercely. "He told me to expect you. He knew more than you thought. Who sent you?"

"No one sent us. Ourselves only," came the voice. "We want to serve Lord Asriel. And the dead man, what did he want you to do with the knife?"

Will had to hesitate.

"He said I should take it to Lord Asriel," he said.

"Then come with us."

"No. Not till I've found Lyra."

He folded the velvet over the alethiometer and put it into his rucksack. Securing it, he swung his father's heavy cloak around him against the rain and crouched where he was, looking steadily at the two shadows.

"Do you tell the truth?" he said.

"Yes."

"Then are you stronger than human beings, or weaker?"

"Weaker. You have true flesh, we have not. Still, you must come with us."

"No. If I'm stronger, you have to obey me. Besides, I have the knife. So I can command you: help me find Lyra. I don't care how long it takes, I'll find her first and then I'll go to Lord Asriel."

The two figures were silent for several seconds. Then they drifted away and spoke together, though Will could hear nothing of what they said.

Finally they came close again, and he heard:

"Very well. You are making a mistake, though you give us no choice. We shall help you find this child."

Will tried to pierce the darkness and see them more clearly, but the rain filled his eyes.

"Come closer so I can see you," he said.

They approached, but seemed to become even more obscure.

"Shall I see you better in daylight?"

"No, worse. We are not of a high order among angels."

"Well, if I can't see you, no one else will, either, so you can stay hidden. Go and see if you can find where Lyra's gone. She surely can't be far away. There was a woman, she'll be with her, the woman took her. Go and search, and come back and tell me what you see."

The angels rose up into the stormy air and vanished. Will felt a great sullen heaviness settle over him; he'd had little strength left before the fight with his father, and now he was nearly finished. All he wanted to do was close his eyes, which were so heavy and so sore with weeping.

He tugged the cloak over his head, clutched the rucksack to his breast, and fell asleep in a moment.

"Nowhere," said a voice.

Will heard it in the depths of sleep and struggled to wake. Eventually (and it took most of a minute, because he was so profoundly unconscious) he managed to open his eyes to the bright morning in front of him.

"Where are you?" he said.

"Beside you," said the angel. "This way."

The sun was newly risen, and the rocks and the lichens and mosses on them shone crisp and brilliant in the morning light, but nowhere could he see a figure.

"I said we would be harder to see in daylight," the voice went on. "You will see us best at half-light, at dusk or dawn; next best in darkness; least of all in the sunshine. My companion and I searched farther down the mountain, and found neither woman nor child. But there is a lake of blue water where she must have camped. There is a dead man there, and a witch eaten by a Specter."

"A dead man? What does he look like?"

"He was in late middle age. Fleshy and smooth-skinned. Silver-gray hair. Dressed in expensive clothes, and with traces of a heavy scent around him."

"Sir Charles," said Will. "That's who it is. Mrs. Coulter must have killed him. Well, that's something good, at least."

"She left traces. My companion has followed them, and he will return when he's found out where she went. I shall stay with you."

Will got to his feet and looked around. The storm had cleared the air, and the morning was fresh and clean, which only made the scene around him more distressing; for nearby lay the bodies of several of the witches who had escorted him and Lyra toward the meeting with his father. Already a brutal-beaked carrion crow was tearing at the face of one of them, and Will could see a bigger bird circling above, as if choosing the richest feast.

Will looked at each of the bodies in turn, but none of them was Serafina Pekkala, the queen of the witch clan, Lyra's particular friend. Then he remembered: hadn't she left suddenly on another errand, not long before the evening?

So she might still be alive. The thought cheered him, and he scanned the horizon for any sign of her, but found nothing but the blue air and the sharp rock in every direction he looked.

"Where are you?" he said to the angel.

"Beside you," came the voice, "as always."

Will looked to his left, where the voice was, but saw nothing.

"So no one can see you. Could anyone else hear you as well as me?"

"Not if I whisper," said the angel tartly.

"What is your name? Do you have names?"

"Yes, we do. My name is Balthamos. My companion is Baruch."

Will considered what to do. When you choose one way out of many, all the ways you don't take are snuffed out like candles, as if they'd never existed. At the moment all Will's choices existed at once. But to keep them all in existence meant doing nothing. He had to choose, after all.

"We'll go back down the mountain," he said. "We'll go to that lake. There might be something there I can use. And I'm getting thirsty anyway. I'll take the way I think it is and you can guide me if I go wrong."

It was only when he'd been walking for several minutes down the pathless, rocky slope that Will realized his hand wasn't hurting. In fact, he hadn't thought of his wound since he woke up.

He stopped and looked at the rough cloth that his father had bound around it after their fight. It was greasy with the ointment he'd spread on it, but there was not a sign of blood; and after the incessant bleeding he'd undergone since the fingers had been lost, this was so welcome that he felt his heart leap almost with joy.

He moved his fingers experimentally. True, the wounds still hurt, but with a different quality of pain: not the deep life-sapping ache of the day before, but a smaller, duller sensation. It felt as if it were healing. His father had done that. The witches' spell had failed, but his father had healed him.

He moved on down the slope, cheered.

It took three hours, and several words of guidance, before he came to the little blue lake. By the time he reached it, he was parched with thirst, and in the baking sun the cloak was heavy and hot, though when he took it off, he missed its cover, for his bare arms and neck were soon burning. He dropped cloak and rucksack and ran the last few yards to the water, to fall on his face and swallow mouthful after freezing mouthful. It was so cold that it made his teeth and skull ache.

Once he'd slaked the thirst, he sat up and looked around. He'd been in no condition to notice things the day before, but now he saw more clearly the intense color of the water, and heard the strident insect noises from all around.

"Balthamos?"

"Always here."

"Where is the dead man?"

"Beyond the high rock on your right."

"Are there any Specters around?"

"No, none. I don't have anything the Specters want, and nor have you."

Will took up his rucksack and cloak and made his way along the edge of the lake and up onto the rock Balthamos had pointed out.

Beyond it a little camp had been set up, with five or six tents and the remains of cooking fires. Will moved down warily in case there was someone still alive and hiding.

But the silence was profound, with the insect scrapings only scratching at the surface of it. The tents were still, the water was placid, with the ripples still drifting slowly out from where he'd been drinking. A flicker of green movement near his foot made him start briefly, but it was only a tiny lizard.

The tents were made of camouflage material, which only made them stand out more among the dull red rocks. He looked in the first and found it empty. So was the second, but in the third he found something valuable: a mess tin and a box of matches. There was also a strip of some dark substance as long and as thick as his forearm. At first he thought it was leather, but in the sunlight he saw it clearly to be dried meat.

Well, he had a knife, after all. He cut a thin sliver and found it chewy and very slightly salty, but full of good flavor. He put the meat and the matches together with the mess tin into his rucksack and searched the other tents, but found them empty.

He left the largest till last.

"Is that where the dead man is?" he said to the air.

"Yes," said Balthamos. "He has been poisoned."

Will walked carefully around to the entrance, which faced the lake. Sprawled beside an overturned canvas chair was the body of the man known in Will's world as Sir Charles Latrom, and in Lyra's as Lord Boreal, the man who stole her alethiometer, which theft in turn led Will to the subtle knife itself. Sir Charles had been smooth, dishonest, and powerful, and now he was dead. His face was distorted unpleasantly, and Will didn't want to look at it, but a glance inside the tent showed that there were plenty of things to steal, so he stepped over the body to look more closely.

His father, the soldier, the explorer, would have known exactly what to take. Will had to guess. He took a small magnifying glass in a steel case, because he could use it to light fires and save his matches; a reel of tough twine; an alloy canteen for water, much lighter than the goatskin flask he had been carrying, and a small tin cup; a small pair of binoculars; a roll of gold coins the size of a man's thumb, wrapped in paper; a first-aid kit; water-purifying tablets; a packet of coffee; three packs of compressed dried fruit; a bag of oatmeal biscuits; six bars of Kendal Mint Cake; a packet of fishhooks and nylon line; and finally, a notebook and a couple of pencils, and a small electric torch.

He packed it all in his rucksack, cut another sliver of meat, filled his belly and then his canteen from the lake, and said to Balthamos:

"Do you think I need anything else?"

"You could do with some sense," came the reply. "Some faculty to enable you to recognize wisdom and incline you to respect and obey it."

"Are you wise?"

"Much more so than you."

"Well, you see, I can't tell. Are you a man? You sound like a man."

"Baruch was a man. I was not. Now he is angelic."

"So...” Will stopped what he was doing, which was arranging his rucksack so the heaviest objects were in the bottom, and tried to see the angel. There was nothing there to see. "So he was a man," he went on, "and then... Do people become angels when they die? Is that what happens?"

"Not always. Not in the vast majority of cases...Very rarely."

"When was he alive, then?"

"Four thousand years ago, more or less. I am much older."

"And did he live in my world? Or Lyra's? Or this one?"

"In yours. But there are myriads of worlds. You know that."

"But how do people become angels?"

"What is the point of this metaphysical speculation?"

"I just want to know."

"Better to stick to your task. You have plundered this dead man's property, you have all the toys you need to keep you alive; now may we move on?"

"When I know which way to go."

"Whichever way we go, Baruch will find us."

"Then he'll still find us if we stay here. I've got a couple more things to do."

Will sat down where he couldn't see Sir Charles's body and ate three squares of the Kendal Mint Cake. It was wonderful how refreshed and strengthened he felt as the food began to nourish him. Then he looked at the alethiometer again. The thirty-six little pictures painted on ivory were each perfectly clear: there was no doubt that this was a baby, that a puppet, this a loaf of bread, and so on. It was what they meant that was obscure.

"How did Lyra read this?" he said to Balthamos.

"Quite possibly she made it up. Those who use these instruments have studied for many years, and even then they can only understand them with the help of many books of reference."

"She wasn't making it up. She read it truly. She told me things she could never have known otherwise."

"Then it is as much of a mystery to me, I assure you," said the angel.

Looking at the alethiometer, Will remembered something Lyra had said about reading it: something about the state of mind she had to be in to make it work. It had helped him, in turn, to feel the subtleties of the silver blade.

Feeling curious, he took out the knife and cut a small window in front of where he was sitting. Through it he saw nothing but blue air, but below, far below, was a landscape of trees and fields: his own world, without a doubt.

So mountains in this world didn't correspond to mountains in his. He closed the window, using his left hand for the first time. The joy of being able to use it again!

Then an idea came to him so suddenly it felt like an electric shock.

If there were myriads of worlds, why did the knife only open windows between this one and his own?

Surely it should cut into any of them.

He held it up again, letting his mind flow along to the very tip of the blade as Giacomo Paradisi had told him, until his consciousness nestled among the atoms themselves and he felt every tiny snag and ripple in the air.

Instead of cutting as soon as he felt the first little halt, as he usually did, he let the knife move on to another and another. It was like tracing a row of stitches while pressing so softly that none of them was harmed.

"What are you doing?" said the voice from the air, bringing him back.

"Exploring," said Will. "Be quiet and keep out of the way. If you come near this you'll get cut, and if I can't see you, I can't avoid you."

Balthamos made a sound of muted discontent. Will held out the knife again and felt for those tiny halts and hesitations.

There were far more of them than he'd thought. And as he felt them without the need to cut through at once, he found that they each had a different quality: this one was hard and definite, that one cloudy; a third was slippery, a fourth brittle and frail...

But among them all there were some he felt more easily than others, and, already knowing the answer, he cut one through to be sure: his own world again.

He closed it up and felt with the knife tip for a snag with a different quality. He found one that was elastic and resistant, and let the knife feel its way through.

And yes! The world he saw through that window was not his own: the ground was closer here, and the landscape was not green fields and hedges but a desert of rolling dunes.

He closed it and opened another: the smoke-laden air over an industrial city, with a line of chained and sullen workers trudging into a factory.

He closed that one, too, and came back to himself. He felt a little dizzy. For the first time he understood some of the true power of the knife, and laid it very carefully on the rock in front of him.

"Are you going to stay here all day?" said Balthamos.

"I'm thinking. You can only move easily from one world to another if the ground's in the same place. And maybe there are places where it is, and maybe that's where a lot of cutting-through happens... And you'd have to know what your own world felt like with the point or you might never get back. You'd be lost forever."

"Indeed. But may we...”

"And you'd have to know which world had the ground in the same place, or there wouldn't be any point in opening it," said Will, as much to himself as to the angel. "So it's not as easy as I thought. We were just lucky in Oxford and Cittagazze, maybe. But I'll just..."

He picked up the knife again. As well as the clear and obvious feeling he got when he touched a point that would open to his own world, there had been another kind of sensation he'd touched more than once: a quality of resonance, like the feeling of striking a heavy wooden drum, except of course that it came, like every other one, in the tiniest movement through the empty air.

There it was. He moved away and felt somewhere else: there it was again.

He cut through and found that his guess was right. The resonance meant that the ground in the world he'd opened was in the same place as this one. He found himself looking at a grassy upland meadow under an overcast sky, in which a herd of placid beasts was grazing, animals such as he'd never seen before, creatures the size of bison, with wide horns and shaggy blue fur and a crest of stiff hair along their backs.

He stepped through. The nearest animal looked up incuriously and then turned back to the grass. Leaving the window open, Will, in the other-world meadow, felt with the knifepoint for the familiar snags and tried them.

Yes, he could open his own world from this one, and he was still high above the farms and hedges; and yes, he could easily find the solid resonance that meant the Cittagazze-world he'd just left.

With a deep sense of relief, Will went back to the camp by the lake, closing everything behind him. Now he could find his way home; now he would not get lost; now he could hide when he needed to, and move about safely.

With every increase in his knowledge came a gain in strength. He sheathed the knife at his waist and swung the rucksack over his shoulder.

"Well, are you ready now?" said that sarcastic voice.

"Yes.  I'll explain  if you like,  but you don't seem very interested."

"Oh, I find whatever you do a source of perpetual fascination. But never mind me. What are you going to say to these people who are coming?"

Will looked around, startled. Farther down the trail, a long way down, there was a line of travelers with packhorses, making their way steadily up toward the lake. They hadn't seen him yet, but if he stayed where he was, they would soon.

Will gathered up his father's cloak, which he'd laid over a rock in the sun. It weighed much less now that it was dry. He looked around: there was nothing else he could carry.

"Let's go farther on," he said.

He would have liked to retie the bandage, but it could wait. He set off along the edge of the lake, away from the travelers, and the angel followed him, invisible in the bright air.

Much later that day they came down from the bare mountains onto a spur covered in grass and dwarf rhododendrons. Will was aching for rest, and soon, he decided, he'd stop.

He'd heard little from the angel. From time to time Balthamos had said, "Not that way," or "There is an easier path to the left," and he'd accepted the advice; but really he was moving for the sake of moving, and to keep away from those travelers, because until the other angel came back with more news, he might as well have stayed where they were.

Now the sun was setting, he thought he could see his strange companion. The outline of a man seemed to quiver in the light, and the air was thicker inside it.

"Balthamos?" he said. "I want to find a stream. Is there one nearby ?"

"There is a spring halfway down the slope," said the angel, "just above those trees."

"Thank you," said Will.

He found the spring and drank deeply, filling his canteen. But before he could go on down to the little wood, there came an exclamation from Balthamos, and Will turned to see his outline dart across the slope toward, what? The angel was visible only as a flicker of movement, and Will could see him better when he didn't look at him directly; but he seemed to pause, and listen, and then launch himself into the air to skim back swiftly to Will.

"Here!" he said, and his voice was free of disapproval and sarcasm for once. "Baruch came this way! And there is one of those windows, almost invisible. Come, come. Come now."

Will followed eagerly, his weariness forgotten. The window, he saw when he reached it, opened onto a dim, tundra-like landscape that was flatter than the mountains in the Cittagazze world, and colder, with an overcast sky. He went through, and Balthamos followed him at once.

"Which world is this?" Will said.

"The girl's own world. This is where they came through. Baruch has gone ahead to follow them."

"How do you know? Do you read his mind?"

"Of course I read his mind. Wherever he goes, my heart goes with him; we feel as one, though we are two."

Will looked around. There was no sign of human life, and the chill in the air was increasing by the minute as the light failed.

"I don't want to sleep here," he said. "We'll stay in the Cittagazze world for the night and come through in the morning. At least there's wood back there, and I can make a fire. And now I know what her world feels like, I can find it with the knife...Oh, Balthamos? Can you take any other shape?"

"Why would I wish to do that?"

"In this world human beings have daemons, and if I go about without one, they'll be suspicious. Lyra was frightened of me at first because of that. So if we're going to travel in her world, you'll have to pretend to be my daemon, and take the shape of some animal. A bird, maybe. Then you could fly, at least."

"Oh, how tedious."

"Can you, though?"

"I could..."

"Do it now, then. Let me see."

The form of the angel seemed to condense and swirl into a little vortex in midair, and then a blackbird swooped down onto the grass at Will's feet.

"Fly to my shoulder," said Will. '''

The bird did so, and then spoke in the angel's familiar acid tone:

"I shall only do this when it's absolutely necessary. It's unspeakably humiliating."

"Too bad," said Will. "Whenever we see people in this world, you become a bird. There's no point in fussing or arguing. Just do it."

The blackbird flew off his shoulder and vanished in midair, and there was the angel again, sulking in the half-light. Before they went back through, Will looked all around, sniffing the air, taking the measure of the world where Lyra was captive.

"Where is your companion now?" he said.

"Following the woman south."

"Then we shall go that way, too, in the morning."

Next day Will walked for hours and saw no one. The country consisted for the most part of low hills covered in short dry grass, and whenever he found himself on any sort of high point, he looked all around for signs of human habitation, but found none. The only variation in the dusty brown-green emptiness was a distant smudge of darker green, which he made for because Balthamos said it was a forest and there was a river there, which led south. When the sun was at its height, he tried and failed to sleep among some low bushes; and as the evening approached, he was footsore and weary.

"Slow progress," said Balthamos sourly.

"I can't help that," said Will. "If you can't say anything useful, don't speak at all."

By the time he reached the edge of the forest, the sun was low and the air heavy with pollen, so much so that he sneezed several times, startling a bird that flew up shrieking from somewhere nearby.

"That was the first living thing I've seen today," Will said.

"Where are you going to camp?" said Balthamos.

The angel was occasionally visible now in the long shadows of the trees. What Will could see of his expression was petulant.

Will said, "I'll have to stop here somewhere. You could help look for a good spot. I can hear a stream, see if you can find it."

The angel disappeared. Will trudged on, through the low clumps of heather and bog myrtle, wishing there was such a thing as a path for his feet to follow, and eyeing the light with apprehension: he must choose where to stop soon, or the dark would force him to stop without a choice.

"Left," said Balthamos, an arm's length away. "A stream and a dead tree for firewood. This way..."

Will followed the angel's voice and soon found the spot he described. A stream splashed swiftly between mossy rocks, and disappeared over a lip into a narrow little chasm dark under the overarching trees. Beside the stream, a grassy bank extended a little way back to bushes and undergrowth.

Before he let himself rest, he set about collecting wood, and soon came across a circle of charred stones in the grass, where someone else had made a fire long before. He gathered a pile of twigs and heavier branches and with the knife cut them to a useful length before trying to get them lit. He didn't know the best way to go about it, and wasted several matches before he managed to coax the flames into life.

The angel watched with a kind of weary patience.

Once the fire was going, Will ate two oatmeal biscuits, some dried meat, and some Kendal Mint Cake, washing it down with gulps of cold water. Balthamos sat nearby, silent, and finally Will said:

"Are you going to watch me all the time? I'm not going anywhere."

"I'm waiting for Baruch. He will come back soon, and then I shall ignore you, if you like."

"Would you like some food?"

Balthamos moved slightly: he was tempted.

"I mean, I don't know if you eat at all," Will said, "but if you'd like something, you're welcome."

"What is that..." said the angel fastidiously, indicating the Kendal Mint Cake.

"Mostly sugar, I think, and peppermint. Here."

Will broke off a square and held it out. Balthamos inclined his head and sniffed. Then he picked it up, his fingers light and cool against Will's palm.

"I think this will nourish me," he said. "One piece is quite enough, thank you."

He sat and nibbled quietly. Will found that if he looked at the fire, with the angel just at the edge of his vision, he had a much stronger impression of him.

"Where is Baruch?" he said. "Can he communicate with you?"

"I feel that he is close. He'll be here very soon. When he returns, we shall talk. Talking is best."

And barely ten minutes later the soft sound of wingbeats came to their ears, and Balthamos stood up eagerly. The next moment, the two angels were embracing, and Will, gazing into the flames, saw their mutual affection. More than affection: they loved each other with a passion.

Baruch sat down beside his companion, and Will stirred the fire, so that a cloud of smoke drifted past the two of them. It had the effect of outlining their bodies so that he could see them both clearly for the first time. Balthamos was slender; his narrow wings were folded elegantly behind his shoulders, and his face bore an expression that mingled haughty disdain with a tender, ardent sympathy, as if he would love all things if only his nature could let him forget their defects. But he saw no defects in Baruch, that was clear. Baruch seemed younger, as Balthamos had said he was, and was more powerfully built, his wings snow-white and massive. He had a simpler nature; he looked up to Balthamos as to the fount of all knowledge and joy. Will found himself intrigued and moved by their love for each other.

"Did you find out where Lyra is?" he said, impatient for news.

"Yes," said Baruch. "There is a Himalayan valley, very high up, near a glacier where the light is turned into rainbows by the ice. I shall draw you a map in the soil so you don't mistake it. The girl is captive in a cave among the trees, kept asleep by the woman."

"Asleep? And the woman's alone? No soldiers with her?"

"Alone, yes. In hiding."

"And Lyra's not harmed?"

"No. Just asleep, and dreaming. Let me show you where they are."

With his pale finger, Baruch traced a map in the bare soil beside the fire. Will took his notebook and copied it exactly. It showed a glacier with a curious serpentine shape, flowing down between three almost identical mountain peaks.

"Now," said the angel, "we go closer. The valley with the cave runs down from the left side of the glacier, and a river of meltwater runs through it. The head of the valley is here..."

He drew another map, and Will copied that; and then a third, getting closer in each time, so that Will felt he could find his way there without difficulty, provided that he'd crossed the four or five thousand miles between the tundra and the mountains. The knife was good for cutting between worlds, but it couldn't abolish distance within them.

"There is a shrine near the glacier," Baruch ended by saying, "with red silk banners half-torn by the winds. And a young girl brings food to the cave. They think the woman is a saint who will bless them if they look after her needs."

"Do they," said Will. "And she's hiding... That's what I don't understand. Hiding from the Church?"

"It seems so."

Will folded the maps carefully away. He had set the tin cup on the stones at the edge of the fire to heat some water, and now he trickled some powdered coffee into it, stirring it with a stick, and wrapped his hand in a handkerchief before picking it up to drink.

A burning stick settled in the fire; a night bird called.

Suddenly, for no reason Will could see, both angels looked up and in the same direction. He followed their gaze, but saw nothing. He had seen his cat do this once: look up alert from her half-sleep and watch something or someone invisible come into the room and walk across. That had made his hair stand up, and so did this.

"Put out the fire," Balthamos whispered.

Will scooped up some earth with his good hand and doused the flames. At once the cold struck into his bones, and he began to shiver. He pulled the cloak around himself and looked up again.

And now there was something to see: above the clouds a shape was glowing, and it was not the moon.

He heard Baruch murmur, "The Chariot? Could it be?"

"What is it?" Will whispered.

Baruch leaned close and whispered back, "They know we're here. They've found us. Will, take your knife and...”

Before he could finish, something hurtled out of the sky and crashed into Balthamos, In a fraction of a second Baruch had leapt on it, and Balthamos was twisting to free his wings. The three beings fought this way and that in the dimness, like great wasps caught in a mighty spider's web, making no sound: all Will could hear was the breaking twigs and