Early one August evening, when most people had already left the park, two men sat confronting one another across a chessboard. It was in the pavilion on the north-west side of the Jardin du Luxembourg. Although the aperitif hour was drawing near, their game was being followed with such close attention by a good dozen spectators that no one dreamed of leaving the scene until the battle had been decided one way or another.

The interest of the small crowd was concentrated on the challenger. He was a youngish man with black hair, pale in the face and with blasé, dark eyes. He uttered not a word; his expression never changed; only from time to time he rolled an unlit cigarette between his fingers. He was the very personification of nonchalance.

No one knew him; no one had ever seen him play before. And yet from the moment he first seated himself at the chessboard, pale, blasé and silent, and put his pieces in position, there emanated from him so strong an aura that everyone was overcome by the certainty that they were in the presence of a quite extraordinary personality of great and masterly talent. Perhaps it was just his attractive and yet unapproachable appearance, his elegant dress and his handsome physique. Or perhaps it was the calmness and self-assurance of his gestures, or the aura of strangeness and peculiarity that surrounded him – whatever it was, before the first pawn had been moved the onlookers were convinced that this man was a chess player of the very first order and that he would achieve the miracle secretly desired by them all of beating the local chess star.