Thomas Pynchon. 
 
Modern Library: 1966. Hardcover with jacket. Very good. Faint layer of foxing on the top edge and smudge on the fore edges of pages 260 - 90. 
 
"Rachel was looking into the mirror at an angle of 45 degrees, and so had a view of the face turned toward the room and the face on the other side, reflected in the mirror; here were time and reverse-time, co-existing, cancelling one another exactly out. Were there many such reference points, scattered through the world, perhaps only at nodes like this room which housed a transient population of the imperfect, the dissatisfied; did real time plus virtual or mirror-time equal zero and thus serve some half-understood moral purpose? Or was it only the mirror world that counted; only a promise of a kind that the inward bow of a nose-bridge or a promontory of extra cartilage at the chin meant a reversal of ill fortune such that the world of the altered would thenceforth run on mirror-time; work and love by mirror-light and be only, till death stopped the heart's ticking (metronome's music) quietly as light ceases to vibrate, an imp's dance under the century's own chandelier. 
'Miss Owglass,' Irving, smiling from the entrance to Schoenmaker's sacristy. Rachel arose, taking her pocketbook, passed the mirror's district, passed through the door to confront the doctor, lazy and hostile behind his kidney-shaped desk. He had the bill, and a carbon, lying on the desk. 'Miss Harvitz's account,' Schoenkaer said. Rachel opened the pocketbook, took out a roll of twenties, dropped them on top of the papers. 
'Count them,' she said. 'This is the balance.'"