“She’s just invested too many hopes in the painting. Surely you can understand that.”

“Oh, I do understand.” He gave a conciliatory smile. “But I can’t allow her to blackmail me.”

“But you plotted behind her back, conspired with the niece and her husband. I call that playing dirty.”

Montegrifo’s smile grew broader. That’s life, he seemed to be saying. He looked at the door through which Menchu had departed.

“What do you think she’ll do now?”

Julia shook her head.

“Nothing. She knows she’s lost the battle.”

“Ambition, Julia, is a perfectly legitimate feeling,” Montegrifo said after a moment. “But where ambition’s concerned, the only sin is failure. Triumph automatically presupposes virtue.” He smiled again, this time into space. “Senora Roch tried to get involved in something that was too big for her… Let’s say” – he blew a smoke ring and let it float up to the ceiling – “that she just wasn’t big enough for her ambitions.” His brown eyes had grown hard, and Julia realised that behind his rigorous mask of politeness, Montegrifo was a dangerous adversary. “I trust she will cause us no further problems,” he continued, “because that would be a sin that would have to be punished. Do you understand? Now, if you don’t mind, let’s talk about our painting.”

Belmonte was alone in the house, and he received Julia and Munoz in the drawing room, sitting in his wheelchair near where The Game of Chess used to hang. The solitary nail and the mark left on the wall created a pathetic air of domestic desolation, of despoliation. Belmonte, who had followed the direction of his visitors’ gaze, smiled sadly.

“I didn’t want to hang anything else there just yet,” he explained, “not for the moment.” He raised one bony hand and waved it in a gesture of resignation. “It’s difficult to get used to…”

“I understand,” said Julia with genuine sympathy.

The old man nodded slowly.

“Yes, I know you do.” He looked at Munoz, doubtless hoping for a show of equal understanding from him, but Munoz remained silent, looking at the empty wall with inexpressive eyes. “I’ve always thought you were an intelligent young woman, right from the very first day.” He looked at Munoz. “Wouldn’t you agree, sir?”

Munoz slowly shifted his eyes away from the wall to the old man and nodded slightly, without saying a word. He seemed immersed in remote thoughts.

“As for your friend,” Belmonte said, and he seemed to be embarrassed, “I’d like you to explain to her… that I really had no choice.”

“Don’t worry. I understand. And Menchu will too.”

“I’m so, glad. They put a lot of pressure on me. Senor Montegrifo made a good offer too. He also undertook to give maximum publicity to the painting’s history.” He stroked his ill-shaven chin. “And, I must confess, that did influence me somewhat,” he sighed softly, “that and the money.”

Julia pointed to the record player.

“Do you play Bach constantly, or is it just a coincidence? I heard that record the last time I was here.”

“The Musical Offering?” Belmonte seemed pleased. “I often listen to it. It’s so complex and ingenious that every now and then I still find something unexpected in it.” He paused, as if recalling something. “Were you aware that there are certain musical themes that seem to sum up a whole life? They’re like mirrors you can peer into and see yourself reflected. In this composition, for example, a theme emerges expressed in different voices and different keys; indeed, sometimes at different speeds, with inverted tonal intervals, or even back to front.” He leaned on the arm of his wheelchair. “Listen. Can you hear it? It begins with a single voice that sings the theme, and then a second voice comes in, starting four tones higher or four tones lower, and that becomes a secondary theme. Each of the voices enters at its own particular time, just like different moments in a life. And when all the voices have come into play, the rules come to an end.” He gave Julia and Munoz a broad, sad smile. “As you see, a perfect analogy of old age.”

Munoz pointed at the wall.

“That nail,” he said rather abruptly, “also seems to symbolise a lot of things.”

Belmonte looked attentively at Munoz and nodded slowly.

“That’s very true,” he confirmed with another sigh. “And sometimes I find myself looking at the place where the picture was and I seem to see it there still. It isn’t there, but I see it. After all these years, I still have it up here.” He tapped his forehead. “The people, the exquisite detail. My favourite parts were always the landscape you can see through the window and the convex mirror on the left, reflecting the foreshortened figures of the players.”

“And the chessboard,” said Munoz.

“Yes, and the chessboard. I often used to reconstruct the position of the pieces on my own chessboard, especially at the beginning, when I inherited it from my poor Ana.”

“Do you play?” asked Munoz casually.

“I used to. Now I hardly ever do. But the truth is, it never occurred to me that you could play that game backwards.” He paused, tapping his hands on his knees. “Playing backwards. It’s odd. Did you know that Bach was very keen on musical inversions? In some of his canons he inverts the theme, elaborating a melody that jumps down a pitch every time the original theme jumps up. The effect can seem strange, but when you get used to it, you find it quite natural. There’s even a canon in the Musical Offering that’s played the opposite way round from the way it’s written.” He looked at Julia. “I think I told you before that Johann Sebastian was an inveterate joker. His work is full of tricks. It’s as if every now and then a note, a modulation or a silence were saying to you: ‘I’ve hidden a message in here: find it.” “

“As in the painting,” said Munoz.

“Yes. With the difference that music doesn’t consist of images, the positioning of chess pieces or, in this case, of vibrations in the air, but of the emotions that those vibrations produce in the brain of each individual. You’d run into serious problems if you tried to apply to music the investigatory methods you used to solve the game in the painting. You’d have to find out which particular note provoked which emotional effect. Or which combinations of notes. Doesn’t that strike you as much more difficult than playing chess?”

Munoz thought about it carefully.

“I don’t think so,” he said at last. “Because the general laws of logic are the same for everything. Music, like chess, follows rules. It’s all a question of working away at it until you isolate a symbol, a key.” One half of his mouth seemed to twist into a smile. “Like the Egyptologists’ Rosetta Stone. Once you have that, it’s just a question of hard work and method. And time.”

Belmonte blinked mockingly.

“Do you think so? Do you really think that all hidden messages can be deciphered? That it’s always possible to reach an exact solution just by the application of method?”

“I’m sure of it. Because there’s a universal system, general laws that allow one to demonstrate what is demonstrable and to discard whatever is not.”

The old man made a sceptical gesture.

“Forgive me, but I really can’t agree with you there. I think that all the divisions, classifications, categorisations and systems that we attribute to the universe are fictitious, arbitrary. There isn’t one that doesn’t contain within it its own contradiction. That’s the opinion of an old man with some experience of these things.”

Munoz shifted a bit in his seat and looked round the room. He didn’t seem very happy with the turn the conversation had taken, but Julia had the impression that he didn’t want to change the subject either. She knew he was not a man to waste words and concluded that he must be after something. Perhaps Belmonte was one of the chess pieces Munoz was studying in order to solve the mystery.