“Yes,” said Petersen, leafing back through the pages. “I’m afraid the psychologist believes that the murders are a way of paying court to you. In M, a general desire for revenge is combined with a much more intense desire to belong to the world that you represent, to have the admiration-even horrified admiration-of those who have rejected him. That’s why for now he’s chosen a way of murdering which he thinks a mathematician would approve of-with a minimum of components, aseptic, without cruelty, almost abstract. As in the early stages of infatuation, M is trying to please you; the murders are offerings. The psychologist thinks that M may be a repressed homosexual who lives alone, but she doesn’t discount the possibility that he’s married and, even now, has a conventional family-life masking his secret activities. She adds that if he gets no sign of a response, this initial seduction stage may be followed by a second, furious stage, in which the murders are more vicious, or target people much closer to you.”
“Well, this psychologist seems almost to know him personally. All that’s missing is for her to tell us that he’s got a mole on his left arm!” exclaimed Seldom. I wasn’t sure if there was only sarcasm in his voice, or a hint of contained irritation as well. I wondered if he’d been shocked by the reference to homosexuality. “I’m afraid that we mathematicians make much more modest conjectures. I have, however, given more thought to what you said and decided that I should maybe tell you my idea.” He took a small notebook from his pocket and, using a fountain pen from Petersen’s desk, quickly drew a few strokes which I couldn’t see. He tore out the page, folded it in two and handed it to Petersen. “Here you have two possible continuations of the series.”
There had been something secretive in the way Seldom folded the paper that Petersen seemed to have caught. He looked at the paper in silence for a moment before folding it again and placing it in a desk drawer. He didn’t ask Seldom any questions. Perhaps in the small duel the two men had engaged in, Petersen was satisfied for now-he had got Seldom to reveal the symbol and didn’t want to bother him with more questions. Or perhaps he simply wanted to discuss it later with him in private. It occurred to me that maybe I ought to get up and leave, but it was Petersen who stood and saw us out with an unexpectedly friendly smile.
“Have you had the results of the second post-mortem?” asked Seldom as we headed towards the door.
“That’s another interesting little mystery,” said Petersen. “At first, the forensic pathologists were puzzled: they found no trace of any known poison in the body. They thought they might even be dealing with a very new drug that leaves no trace, of which I’d never heard. But I think I’ve solved this at least,” he said, and for the first time I saw something like pride in his eyes. “The murderer may think he’s very clever, but we policemen do a bit of thinking from time to time as well.”
Fourteen
We left the police station in silence and walked back along St Aldates without a word until we reached Carfax Tower.
“I need to buy tobacco,” said Seldom. “Would you like to come with me to the Covered Market?”
I nodded and we turned down the High. I hadn’t said a word since we left the police station. Seldom smiled to himself.
“You’re offended because I didn’t tell you what the symbol was. But believe me, I have a very good reason.”
“A different reason from the one you gave me in the park yesterday? Now that you’ve shown it to Petersen, I can’t see why there should be any adverse consequences of me knowing it.”
“There could be…other consequences,” said Seldom. “But that’s not exactly why I haven’t told you. I don’t want my conjectures to influence yours. It’s what I do with my graduate students: I try not to get ahead of them with my own reasoning. The most valuable time in a mathematician’s thinking process is the moment when he has his first solitary intuition about a problem. Though you may not believe it, I have more faith in you than in myself to find the correct answer. You were there at the beginning, and the beginning, as Aristotle would say, is half of everything. I’m sure you noticed something, though you may not yet know what. And above all, you’re not English. The first crime was the matrix. The circle is like the zero in natural numbers, a symbol of maximum uncertainty but which also determines everything.”
We entered the market and Seldom took his time choosing a tobacco mix at a tobacconist’s run by a woman of Indian appearance. The woman, who got up from her stool to serve him, was wearing a saffron-coloured robe and an earring like a silver coil hung from her left ear. On closer inspection, I saw that it was in fact a snake. I suddenly remembered what Seldom had said about the ouroboros of the Gnostics and couldn’t help asking the woman about the symbol.
Tapping the serpent’s head, she said:
“Nothing and everything. The emptiness of every separate thing, and the totality that embraces them all. Difficult, difficult to understand. Absolute reality, beyond negation. Eternity, that which has no beginning and no end. Reincarnation.”
She carefully weighed out the tobacco and exchanged a few words with Seldom as she handed him his change. We made our way out through the maze of stalls. In the arcade, we saw Beth standing by a little table, handing out leaflets for the Sheldonian Orchestra. They were holding a charity concert and the members of the orchestra, she told us, took turns selling tickets. Seldom picked up one of the programmes.
“It’s an orchestral concert at Blenheim Palace, with fireworks during one of the pieces,” he said. “I’m afraid you can’t leave Oxford without going, at least once, to a concert with fireworks. Allow me to buy you a ticket.” And he took the money for two tickets from his pocket.
I hadn’t spoken to Beth since my trip to London. As she tore out the tickets and wrote the seat numbers, I had the feeling that she was avoiding my gaze. The meeting seemed to embarrass her.
“Will I get to hear you play at last?” I asked.
“It’ll probably be my last concert,” she said, her eyes meeting Seldom’s for a moment. She went on, as if this were something she hadn’t told anyone yet and she wasn’t sure he would approve: “I’m getting married at the end of the month and I’m going to take some time off. I don’t think I’ll carry on playing afterwards.”
“That’s a pity,” said Seldom.
“That I’m stopping playing or that I’m getting married?” asked Beth, and she smiled joylessly at her own joke.
“Both!” I said. They laughed openly, as if my answer had provided unexpected relief. As I watched them laughing, I remembered what Seldom had said about me not being English. There was something restrained even in this spontaneous laughter, as if it were an unaccustomed liberty and they shouldn’t take it too far. Seldom could have objected that he was Scottish, of course, but even so, in their gestures, or rather in their careful economy of gestures, they had an undeniable air in common.
We emerged on to Cornmarket Street and I pointed out to Seldom a notice that I had seen earlier on one of the boards at the entrance to the Bodleian Library. It was for a round-table discussion in which Inspector Petersen and a local crime writer would be taking part: “Is there such a thing as the perfect crime?” The title made Seldom stop for a moment.
“Do you think this is some kind of bait Petersen is putting out?” he asked. The thought hadn’t occurred to me.
“No, the poster’s been up for nearly a month. And I assume that if they were laying a trap for the murderer they would have invited you too.”
“Perfect Crimes…I consulted a book with that same title when I was trying to establish the parallels between logic and criminal investigations. The book cited dozens of cases that have never been solved. The most interesting, for my purposes, was the case of a doctor, Howard Green, who formulated the problem most precisely. He wanted to kill his wife and wrote a diary setting out, in a truly scientific, detailed manner, all the possible adverse ramifications. It would be easy, he concluded, to kill her in such a way that the police couldn’t pin the blame on anyone with certainty. He proposed fourteen different methods, some highly ingenious. It would be much more difficult to ensure that he himself remained above suspicion forever.