Lord Roke hadn't told her everything that he'd learned from Lord Asriel. The allies had been tracking the flight of all kinds of beings in the air above the frontiers of the Republic, and had noticed a concentration of what might have been angels, and might have been something else entirely, in the west. They had sent patrols out to investigate, but so far they had learned nothing: whatever it was that hung there had wrapped itself in impenetrable fog.

The spy thought it best not to trouble Mrs. Coulter with that, though; she was exhausted. Let her sleep, he decided, and he moved silently about the room, listening at the door, watching out of the window, awake and alert.

An hour after she had first come into the room, he heard a quiet noise outside the door: a faint scratch and a whisper. At the same moment a dim light outlined the door. Lord Roke moved to the farthest corner and stood behind one of the legs of the chair on which Mrs. Coulter had thrown her clothes.

A minute went by, and then the key turned very quietly in the lock. The door opened an inch, no more, and then the light went out.

Lord Roke could see well enough in the dim glow through the thin curtains, but the intruder was having to wait for his eyes to adjust. Finally the door opened farther, very slowly, and the young priest Brother Louis stepped in.

He crossed himself and tiptoed to the bed. Lord Roke prepared to spring, but the priest merely listened to Mrs. Coulter's steady breathing, looked closely to see whether she was asleep, and then turned to the bedside table.

He covered the bulb of the battery light with his hand and switched it on, letting a thin gleam escape through his fingers. He peered at the table so closely that his nose nearly touched the surface, but whatever he was looking for, he didn't find it. Mrs. Coulter had put a few things there before she got into bed-a couple of coins, a ring, her watch-but Brother Louis wasn't interested in those.

He turned to her again, and then he saw what he was looking for, uttering a soft hiss between his teeth. Lord Roke could see his dismay: the object of his search was the locket on the gold chain around Mrs. Coulter's neck.

Lord Roke moved silently along the skirting board toward the door.

The priest crossed himself again, for he was going to have to touch her. Holding his breath, he bent over the bed-and the golden monkey stirred.

The young man froze, hands outstretched. His rabbit daemon trembled at his feet, no use at all: she could at least have kept watch for the poor man, Lord Roke thought. The monkey turned over in his sleep and fell still again.

After a minute poised like a waxwork, Brother Louis lowered his shaking hands to Mrs. Coulter's neck. He fumbled for so long that Lord Roke thought the dawn would break before he got the catch undone, but finally he lifted the locket gently away and stood up.

Lord Roke, as quick and as quiet as a mouse, was out of the door before the priest had turned around. He waited in the dark corridor, and when the young man tiptoed out and turned the key, the Gallivespian began to follow him.

Brother Louis made for the tower, and when the President opened his door, Lord Roke darted through and made for the prie-dieu in the corner of the room. There he found a shadowy ledge where he crouched and listened.

Father MacPhail was not alone: Fra Pavel, the alethiometrist, was busy with his books, and another figure stood nervously by the window. This was Dr. Cooper, the experimental theologian from Bolvangar. They both looked up.

"Well done, Brother Louis," said the President. "Bring it here, sit down, show me, show me. Well done!"

Fra Pavel moved some of his books, and the young priest laid the gold chain on the table. The others bent over to look as Father MacPhail fiddled with the catch. Dr. Cooper offered him a pocketknife, and then there was a soft click.

"Ah!" sighed the President.

Lord Roke climbed to the top of the desk so that he could see. In the naphtha lamplight there was a gleam of dark gold: it was a lock of hair, and the President was twisting it between his fingers, turning it this way and that.

"Are we certain this is the child's?" he said.

"I am certain," came the weary voice of Fra Pavel.

"And is there enough of it, Dr. Cooper?"

The pale-faced man bent low and took the lock from Father MacPhail's fingers. He held it up to the light.

"Oh yes," he said. "One single hair would be enough. This is ample."

"I'm very pleased to hear it," said the President. "Now, Brother Louis, you must return the locket to the good lady's neck."

The priest sagged faintly: he had hoped his task was over. The President placed the curl of Lyra's hair in an envelope and shut the locket, looking up and around as he did so, and Lord Roke had to drop out of sight.

"Father President," said Brother Louis, "I shall of course do as you command, but may I know why you need the child's hair?"

"No, Brother Louis, because it would disturb you. Leave these matters to us. Off you go."

The young man took the locket and left, smothering his resentment. Lord Roke thought of going back with him and waking Mrs. Coulter just as he was trying to replace the chain, in order to see what she'd do; but it was more important to find out what these people were up to.

As the door closed, the Gallivespian went back into the shadows and listened.

"How did you know where she had it?" said the scientist.

"Every time she mentioned the child," the President said, "her hand went to the locket. Now then, how soon can it be ready?"

"A matter of hours," said Dr. Cooper.

"And the hair? What do you do with that?"

"We place the hair in the resonating chamber. You understand, each individual is unique, and the arrangement of genetic particles quite distinct... Well, as soon as it's analyzed, the information is coded in a series of anbaric pulses and transferred to the aiming device. That locates the origin of the material, the hair, wherever she may be. It's a process that actually makes use of the Barnard-Stokes heresy, the many-worlds idea..."

"Don't alarm yourself, Doctor. Fra Pavel has told me that the child is in another world. Please go on. The force of the bomb is directed by means of the hair?"

"Yes. To each of the hairs from which these ones were cut. That's right."

"So when it's detonated, the child will be destroyed, wherever she is?"

There was a heavy indrawn breath from the scientist, and then a reluctant "Yes." He swallowed, and went on, "The power needed is enormous. The anbaric power. Just as an atomic bomb needs a high explosive to force the uranium together and set off the chain reaction, this device needs a colossal current to release the much greater power of the severance process. I was wondering-"

"It doesn't matter where it's detonated, does it?"

"No. That is the point. Anywhere will do."

"And it's completely ready?"

"Now we have the hair, yes. But the power, you see-"

"I have seen to that. The hydro-anbaric generating station at Saint-Jean-les-Eaux has been requisitioned for our use. They produce enough power there, wouldn't you say?"

"Yes," said the scientist.

"Then we shall set out at once. Please go and see to the apparatus, Dr. Cooper. Have it ready for transportation as soon as you can. The weather changes quickly in the mountains, and there is a storm on the way."

The scientist took the little envelope containing Lyra's hair and bowed nervously as he left. Lord Roke left with him, making no more noise than a shadow.

As soon as they were out of earshot of the President's room, the Gallivespian sprang. Dr. Cooper, below him on the stairs, felt an agonizing stab in his shoulder and grabbed for the banister; but his arm was strangely weak, and he slipped and tumbled down the whole flight, to land semiconscious at the bottom.

Lord Roke hauled the envelope out of the man's twitching hand with some difficulty, for it was half as big as he was, and set off in the shadows toward the room where Mrs. Coulter was asleep.

The gap at the foot of the door was wide enough for him to slip through. Brother Louis had come and gone, but he hadn't dared to try and fasten the chain around Mrs. Coulter's neck: it lay beside her on the pillow.

Lord Roke pressed her hand to wake her up. She was profoundly exhausted, but she focused on him at once and sat up, rubbing her eyes.

He explained what had happened and gave her the envelope.

"You should destroy it at once," he told her. "One single hair would be enough, the man said."

She looked at the little curl of dark blond hair and shook her head.

"Too late for that," she said. "This is only half the lock I cut from Lyra. He must have kept back some of it."

Lord Roke hissed with anger.

"When he looked around!" he said. "Ach-I moved to be out of his sight-he must have set it aside then..."

"And there's no way of knowing where he'll have put it," said Mrs. Coulter. "Still, if we can find the bomb-"

"Shh!"

That was the golden monkey. He was crouching by the door, listening, and then they heard it, too: heavy footsteps hurrying toward the room.

Mrs. Coulter thrust the envelope and the lock of hair at Lord Roke, who took it and leapt for the top of the wardrobe. Then she lay down next to her daemon as the key turned noisily in the door.

"Where is it? What have you done with it? How did you attack Dr. Cooper?" said the President's harsh voice as the light fell across the bed.

Mrs. Coulter threw up an arm to shade her eyes and struggled to sit up.

"You do like to keep your guests entertained," she said drowsily. "Is this a new game? What do I have to do? And who is Dr. Cooper?"

The guard from the gatehouse had come in with Father MacPhail and was shining a torch into the corners of the room and under the bed. The President was slightly disconcerted: Mrs. Coulter's eyes were heavy with sleep, and she could hardly see in the glare from the corridor light. It was obvious that she hadn't left her bed.

"You have an accomplice," he said. "Someone has attacked a guest of the College. Who is it? Who came here with you? Where is he?"

"I haven't the faintest idea what you're talking about. And what's this... ?"

Her hand, which she'd put down to help herself sit up, had found the locket on the pillow. She stopped, picked it up, and looked at the President with wide-open sleepy eyes, and Lord Roke saw a superb piece of acting as she said, puzzled, "But this is my... what's it doing here? Father MacPhail, who's been in here? Someone has taken this from around my neck. And-where is Lyra's hair? There was a lock of my child's hair in here. Who's taken it? Why? What's going on?" There was a lock of my child's hair in here. Who's taken it? Why? What's going on?"

And now she was standing, her hair disordered, passion in her voice-plainly just as bewildered as the President himself.

Father MacPhail took a step backward and put his hand to his head.

"Someone else must have come with you. There must be an accomplice," he said, his voice rasping at the air. "Where is he hiding?"

"I have no accomplice," she said angrily. "If there's an invisible assassin in this place, I can only imagine it's the Devil himself. I dare say he feels quite at home."

Father MacPhail said to the guard, "Take her to the cellars. Put her in chains. I know just what we can do with this woman; I should have thought of it as soon as she appeared."

She looked wildly around and met Lord Roke's eyes for a fraction of a second, glittering in the darkness near the ceiling. He caught her expression at once and understood exactly what she meant him to do.

TWENTY-FIVE.

SAINT-JEAN-LES-EAUX.

A bracelet of bright hair about the bone ... JOHN DONNE The cataract of Saint-Jean-les-Eaux plunged between pinnacles of rock at the eastern end of a spur of the Alps, and the generating station clung to the side of the mountain above it. It was a wild region, a bleak and battered wilderness, and no one would have built anything there at all had it not been for the promise of driving great anbaric generators with the power of the thousands of tons of water that roared through the gorge.

It was the night following Mrs. Coulter's arrest, and the weather was stormy. Near the sheer stone front of the generating station, a zeppelin slowed to a hover in the buffeting wind. The searchlights below the craft made it look as if it were standing on several legs of light and gradually lowering itself to lie down.

But the pilot wasn't satisfied; the wind was swept into eddies and cross-gusts by the edges of the mountain. Besides, the cables, the pylons, the transformers were too close: to be swept in among them, with a zeppelin full of inflammable gas, would be instantly fatal. Sleet drummed slantwise at the great rigid envelope of the craft, making a noise that almost drowned the clatter and howl of the straining engines, and obscuring the view of the ground.

"Not here," the pilot shouted over the noise. "We'll go around the spur."

Father MacPhail watched fiercely as the pilot moved the throttle forward and adjusted the trim of the engines. The zeppelin rose with a lurch and moved over the rim of the mountain. Those legs of light suddenly lengthened and seemed to feel their way down the ridge, their lower ends lost in the whirl of sleet and rain.

"You can't get closer to the station than this?" said the President, leaning forward to let his voice carry to the pilot.

"Not if you want to land," the pilot said.

"Yes, we want to land. Very well, put us down below the ridge."

The pilot gave orders for the crew to prepare to moor. Since the equipment they were going to unload was heavy as well as delicate, it was important to make the craft secure. The President settled back, tapping his fingers on the arm of his seat, gnawing his lip, but saying nothing and letting the pilot work unflustered.

From his hiding place in the transverse bulkheads at the rear of the cabin, Lord Roke watched. Several times during the flight his little shadowy form had passed along behind the metal mesh, clearly visible to anyone who might have looked, if only they had turned their heads; but in order to hear what was happening, he had to come to a place where they could see him. The risk was unavoidable.

He edged forward, listening hard through the roar of the engines, the thunder of the hail and sleet, the high-pitched singing of the wind in the wires, and the clatter of booted feet on metal walkways. The flight engineer called some figures to the pilot, who confirmed them, and Lord Roke sank back into the shadows, holding tight to the struts and beams as the airship plunged and tilted.

Finally, sensing from the movement that the craft was nearly anchored, he made his way back through the skin of the cabin to the seats on the starboard side.

There were men passing through in both directions: crew members, technicians, priests. Many of their daemons were dogs, brimming with curiosity. On the other side of the aisle, Mrs. Coulter sat awake and silent, her golden daemon watching everything from her lap and exuding malice.

Lord Roke waited for the chance and then darted across to Mrs. Coulter's seat, and was up in the shadow of her shoulder in a moment.

"What are they doing?" she murmured.

"Landing. We're near the generating station."

"Are you going to stay with me, or work on your own?" she whispered.

"I'll stay with you. I'll have to hide under your coat."

She was wearing a heavy sheepskin coat, uncomfortably hot in the heated cabin, but with her hands manacled she couldn't take it off.

"Go on, now," she said, looking around, and he darted inside the breast, finding a fur-lined pocket where he could sit securely. The golden monkey tucked Mrs. Coulter's silk collar inside solicitously, for all the world like a fastidious couturier attending to his favorite model, while all the time making sure that Lord Roke was completely hidden in the folds of the coat.

He was just in time. Not a minute later a soldier armed with a rifle came to order Mrs. Coulter out of the airship.