“But before, when you were talking to us about a battle between two philosophies, you were talking about the murderer, about our mystery player,” said Julia. “This time it seems that you are interested in winning. Is that right?”

Munoz’s gaze again drifted off to some indeterminate point in space.

“I suppose it is. Yes, this time I do want to win.”

“Why?”

“Instinct. I’m a chess player, a good one. Someone is trying to provoke me, and that forces me to pay close attention to the moves he makes. The truth is, I have no choice.”

Cesar smiled mockingly, lighting one of his special gold-filter cigarettes.

“Sing, O Muse,” he recited, in a tone of festive parody, “of the fury of our grieving Munoz, who, at last, has resolved to leave his tent. Our friend is finally going to war. Until now he has acted only as an outside observer, so I’m pleased at last to see him swear allegiance to the flag. A hero malgre lui, but a hero for all that. It’s just a shame,” a shadow crossed his smooth, pale brow, “that it’s such a devilishly subtle war.”

Munoz looked at Cesar with interest.

“It’s odd you should say that.”

“Why?”

“Because chess is, in fact, a substitute for war and for something else as well. I mean for patricide.” He looked at them uncertainly, as if asking them not to take his words too seriously. “Chess is all about getting the king into check, you see. It’s about killing the father. I would say that chess has more to do with the art of murder than it does with the art of war.”

An icy silence chilled the air around the table. Cesar was looking at Munoz’s now sealed lips, screwing up his eyes a little, as if troubled by the smoke from his cigarette. His look was one of frank admiration, as if Munoz had just opened a door that hinted at unfathomable mysteries contained within.

“Amazing,” he murmured.

Julia seemed equally mesmerised by Munoz. However mediocre and insignificant he might appear, this man with his large ears and his timid, rumpled air knew exactly what he was talking about. In the mysterious labyrinth, even the idea of which made men tremble with impotence and fear, Munoz was the only one who knew how to interpret the signs, the only one who possessed the keys that allowed him to come and go without being devoured by the Minotaur. And there, sitting before the remains of her barely touched lasagne, Julia knew with a mathematical, almost a chess player’s certainty that, in his way, this man was the strongest of the three of them. His judgment was not dimmed by prejudices about his opponent, the mystery player and potential murderer. He considered the enigma with the same egotistical, scientific coldness that Sherlock Holmes used to solve the problems set him by the sinister Professor Moriarty. Munoz would not play that game to the end out of a sense of justice; his motive was not ethical, but logical. He would do it simply because h: was a player whom chance had placed on this side of the chessboard, just as – and Julia shuddered at the thought -it could have placed him on the other side. Whether he played White or Black, she realised, was a matter of complete indifference to him. All that mattered to him was that, for the first time in his life, he was interested in playing a game to the end.

Her eyes met Cesar’s and she knew he was thinking the same thing. It was he who spoke first, in a low voice, as if fearing, as she did, to extinguish the light in Munoz’s eyes.

“Killing the king…” Cesar put the cigarette holder slowly to his lips and inhaled a precise amount of smoke. “That’s very interesting. I mean the Freudian interpretation of the game. I had no idea chess had anything to do with such unpleasant things.”

Munoz, his head slightly to one side, seemed absorbed in his own thoughts.

“It’s usually the father who teaches the child his first moves in the game. And the dream of any son who plays chess is to beat his father. To kill the king. Besides, it soon becomes evident in chess that the father, or the king, is the weakest piece on the board. He’s under continual attack, in constant need of protection, of such tactics as castling, and he can only move one square at a time. Paradoxically, the king is also indispensable. The king gives the game its name, since the word ‘chess’ derives from the Persian word shah meaning king, and is pretty much the same in most languages.”

“And the queen?” asked Julia.

“She’s the mother and the wife. In any attack on the king, she provides the most efficient defence. The queen is the piece with the best and most effective resources. And on either side of the king and the queen is the bishop: the one who blesses the union and helps in the fight. Not forgetting the Arab faros, the horse that crosses the enemy lines, the knight. In fact, the problem existed long before Van Huys painted his Game of Chess; men have been trying to solve it for fourteen hundred years.”

Munoz paused, and seemed about to say more, but instead of words, what appeared on his lips was that brief suggestion of a smile.

“Sometimes,” he said at last, as if it were an enormous effort to formulate his thoughts, “I wonder if chess is something man invented or if he merely discovered it. It’s as if it were something that has always been there, since the beginning of the universe. Like whole numbers.”

As if in a dream, Julia heard the sound of a seal being broken and, for the first time, she was properly aware of the situation: a vast chessboard embracing both past and present, Van Huys and herself, even Alvaro, Cesar, Montegrifo, the Belmontes, Menchu and Munoz. And she suddenly felt such intense fear that she had to make an almost physical effort not to express it out loud. The fear must have shown in her face because both Cesar and Munoz gave her a worried look.

“I’m all right,” she said, shaking her head as if that might help calm her thoughts. Then she took from her pocket the list of different levels that existed in the painting, according to Munoz’s first interpretation. “Have a look at this.”

Munoz studied the sheet of paper and passed it to Cesar without comment.

“What do you think?” asked Julia.

Cesar was hesitant.

“Most disturbing,” he said. “But perhaps we’re being too literary about it.” He glanced again at Julia’s diagram. “I can’t make up my mind whether we’re all racking our brains over something really profound or something absolutely trivial.”

Julia didn’t reply. She was staring at Munoz. He placed the piece of paper on the table, took a pen from his pocket and added something and passed it back to her.

“Now there’s another level,” he said in a worried voice. “You’re at least as involved as any of the others.”

“That’s what I thought,” said Julia.

“Level 6 is the one that contains all the others.” Munoz pointed to the list. “Whether you like it or not, you’re there in it too.”

“That means,” said Julia, looking at him with wide-open eyes, “that the person who may have murdered Alvaro, the same one who sent us that card, is playing some kind of mad chess game. A game in which not only I, but we, all of us, are pieces. Is that right?”

There was no sadness in Munoz’s face, only a sort of expectant curiosity, as if fascinating conclusions could be drawn from what she’d just said, conclusions he would be only too happy to comment on.

“I’m glad,” he replied at last, and the diffuse smile returned to his lips, “that you’ve both finally realised that.”

Menchu had made herself up with millimetric precision and had chosen her clothes to calculated effect: a short, very tight skirt and an extremely elegant black leather jacket over a cream sweater that emphasised her bosom to an extent that Julia instantly decried as “scandalous”. Perhaps foreseeing this, Julia had opted that afternoon for an informal look, choosing to wear moccasins, jeans, a suede bomber jacket and a silk scarf. As Cesar would have said, had he seen them parking Julia’s Fiat outside Claymore’s, they could easily have passed for mother and daughter.