This question does not crystallize in Ulrich’s thoughts until he meets his sister Agathe more than seven hundred pages into the novel. Her name—which, significantly, is derived from the Greek word for “good”—has not been mentioned before: she appears, as it were, out of nowhere. As their relationship unfolds (how apt the floral image in that metaphor seems here: a continual, unhurried opening and disclosure), one has the impression that she has been present to him all along precisely by her absence. In all his dealings with both men and women before meeting Agathe, Ulrich has displayed charm, diplomacy, lust, aloofness, private scorn, occasional stirrings of compassion, but on the whole a notable absence of tenderness, let alone love. Something was missing. Now she is here.

Their encounter marks the beginning of a radical departure for Ulrich and for the novel itself. The narrator describes it in a rare address to the reader several chapters further on:

But whoever has not already picked up the clues to what was developing between this brother and sister, let him put aside this account, for it describes an adventure he will never be able to approve of: a voyage to the edge of the possible, leading past, and perhaps not always steering clear of, the dangers of the impossible and the unnatural, indeed of the repulsive; a “limit case,” as Ulrich later called it, of restricted and special validity, reminiscent of the freedom with which mathematics occasionally employs the absurd in order to arrive at truth. He and Agathe came upon a path that had much in common with the business of the God-possessed, but they walked it without piety, without believing in God or the soul, or even in a Beyond or a Once Again; they had come upon it as human beings belonging to this world and walked it as such: and just that was the remarkable thing about it.

•

Agathe and Ulrich withdraw from society, eventually retreating to Ulrich’s little rococo château in the middle of Vienna as if to an island. For a while, in obedience to social pressure, they attend elegant soirees with the idea of finding a new husband for Agathe (she intends to divorce the man she is married to), and Ulrich pays visits to various friends and acquaintances, including the luminaries of the Parallel Campaign. But before long, these worldly forays recede from the novel’s horizon, until the siblings’ retreat becomes near absolute. Their private adventure, both spiritual and erotic, becomes the central theme of the novel. That is the principal reason why it was possible for the editor of this book, without violating the novel’s integrity, to excerpt thirty-six chapters, all of them centered on Agathe and Ulrich, as a self-contained narrative, in effect a novel within the novel. A loss of complexity and illuminating contrast is unavoidably entailed in this experiment; but that loss, I believe, is offset by the gain of unbroken concentration on what Agathe calls “the last possible love story.”