She focused her mind on the central skull and asked: What sort of person did this skull belong to, and why did they have those holes made in it?

As she stood concentrating in the dusty light that filtered through the glass roof and slanted down past the upper galleries, she didn't notice that she was being watched.

A powerful-looking man in his sixties, wearing a beautifully tailored linen suit and holding a Panama hat, stood on the gallery above and looked down over the iron railing.

His gray hair was brushed neatly back from his smooth, tanned, barely wrinkled forehead. His eyes were large, dark and long-lashed and intense, and every minute or so his sharp, dark-pointed tongue peeped out at the corner of his lips and flicked across them moistly. The snowy handkerchief in his breast pocket was scented with some heavy cologne like those hothouse plants so rich you can smell the decay at their roots.

He had been watching Lyra for some minutes. He had moved along the gallery above as she moved about below, and when she stood still by the case of skulls, he watched her closely, taking in all of her: her rough, untidy hair, the bruise on her cheek, the new clothes, her bare neck arched over the alethiometer, her bare legs.

He shook out the breast-pocket handkerchief and mopped his forehead, and then made for the stairs.

Lyra, absorbed, was learning strange things. These skulls were unimaginably old; the cards in the case said simply BRONZE AGE, but the alethiometer, which never lied, said that the man whose skull it was had lived 33,254 years before the present day, and that he had been a sorcerer, and that the hole had been made to let the gods into his head. And then the alethiometer, in the casual way it sometimes had of answering a question Lyra hadn't asked, added that there was a good deal more Dust around the trepanned skulls than around the one with the arrowhead.

What in the world could that mean? Lyra came out of the focused calm she shared with the alethiometer and drifted back to the present moment to find herself no longer alone. Gazing into the next case was an elderly man in a pale suit, who smelled sweet. He reminded her of someone, but she couldn't think who.

He became aware of her staring at him, and looked up with a smile.

"You're looking at the trepanned skulls?" he said. "What strange things people do to themselves."

"Mm," she said expressionlessly.

"D'you know, people still do that?"

"Yeah," she said.

"Hippies, you know, people like that. Actually, you're far too young to remember hippies. They say it's more effective than taking drugs."

Lyra had put the alethiometer in her rucksack and was wondering how she could get away. She still hadn't asked it the main question, and now this old man was having a conversation with her. He seemed nice enough, and he certainly smelled nice. He was closer now. His hand brushed hers as he leaned across the case.

"Makes you wonder, doesn't it? No anesthetic, no disinfectant, probably done with stone tools. They must have been tough, mustn't they? I don't think I've seen you here before. I come here quite a lot. What's your name?"

"Lizzie," she said comfortably.

"Lizzie. Hello, Lizzie. I'm Charles. Do you go to school in Oxford?"

She wasn't sure how to answer. "No," she said.

"Just visiting? Well, you've chosen a wonderful place to look at. What are you specially interested in?"

She was more puzzled by this man than by anyone she'd met for a long time. On the one hand he was kind and friendly and very clean and smartly dressed, but on the other hand Pantalaimon, inside her pocket, was plucking at her attention and begging her to be careful, because he was half-remembering something too; and from somewhere she sensed, not a smell, but the idea of a smell, and it was the smell of dung, of putrefaction. She was reminded of Lofur Raknison's palace, where the air was perfumed but the floor was thick with filth.

"What am I interested in?" she said. "Oh, all sorts of things, really. Those skulls I got interested in just now, when I saw them there. I shouldn't think anyone would want that done. It's horrible."

"No, I wouldn't enjoy it myself, but I promise you it does happen. I could take you to meet someone who's done it," he said, looking so friendly and helpful that she was very nearly tempted. But then out came that little dark tongue point, as quick as a snake's, flick-moisten, and she shook her head.

"I got to go," she said. "Thank you for offering, but I better not. Anyway, I got to go now because I'm meeting someone. My friend," she added. "Who I'm staying with."

"Yes, of course," he said kindly. "Well, it was nice talking to you. Bye-bye, Lizzie."

"Bye," she said.

"Oh, just in case, here's my name and address," he said, handing her a card. "Just in case you want to know more about things like this."

"Thank you," she said blandly, and put it in the little pocket on the back of her rucksack before leaving. She felt he was watching her all the way out.

Once she was outside the museum, she turned in to the park, which she knew as a field for cricket and other sports, and found a quiet spot under some trees and tried the alethiometer again.

This time she asked where she could find a Scholar who knew about Dust. The answer she got was simple: it directed her to a certain room in the tall square building behind her. In fact, the answer was so straightforward, and came so abruptly, that Lyra was sure the alethiometer had more to say: she was beginning to sense now that it had moods, like a person, and to know when it wanted to tell her more.

And it did now. What it said was: You must concern yourself with the boy. Your task is to help him find his father. Put your mind to that.

She blinked. She was genuinely startled. Will had appeared out of nowhere in order to help her; surely that was obvious. The idea that she had come all this way in order to help him took her breath away.

But the alethiometer still hadn't finished. The needle twitched again, and she read: Do not lie to the Scholar.

She folded the velvet around the alethiometer and thrust it into the rucksack out of sight. Then she stood and looked around for the building where her Scholar would be found, and set off toward it, feeling awkward and defiant.

Will found the library easily enough, where the reference librarian was perfectly prepared to believe that he was doing some research for a school geography project and helped him find the bound copies of The Timesindex for the year of his birth, which was when his father had disappeared. Will sat down to look through them. Sure enough, there were several references to John Parry, in connection with an archaeological expedition.

Each month, he found, was on a separate roll of microfilm. He threaded each in turn into the projector, scrolled through to find the stories, and read them with fierce attention. The first story told of the departure of an expedition to the north of Alaska. The expedition was sponsored by the Institute of Archaeology at Oxford University, and it was going to survey an area in which they hoped to find evidence of early human settlements. It was accompanied by John Parry, late of the Royal Marines, a professional explorer.

The second story was dated six weeks later. It said briefly that the expedition had reached the North American Arctic Survey Station at Noatak in Alaska.

The third was dated two months after that. It said that there had been no reply to signals from the Survey Station, and that John Parry and his companions were presumed missing.

There was a brief series of articles following that one, describing the parties that had set out fruitlessly to look for them, the search flights over the Bering Sea, the reaction of the Institute of Archaeology, interviews with relatives…