Since there had been no date or day of the week specified on the postcard, I assumed I was supposed to turn up at the earliest possible moment, i.e., the following day. I wondered what John would have done if Rogier van der Weyden had been born in, say, 1860—and then cursed myself for stupidity. Naturally he would select a painter whose vital statistics coincided with the time he found convenient.

On a wintry weekday when most people were busy Christmas shopping, the museum was not crowded. There were only half a dozen art-lovers in the room dominated by van der Weyden’s glorious rendition of the Nativity; a quick glance assured me that John was not one of them.

Strictly speaking, the painting is not a Nativity. Christian iconography is painstakingly specialized. Except for the Crucifixion, no subject was so popular with artists as the birth of Christ, and every separate incident has its own designation and its own artistic traditions. This painting, which had once adorned an altar in Cologne, shows the Adoration of the Magi—the Anbetung der Könige. Though the Virgin is not at the center of the canvas, the composition is so admirable that the beholder’s eye is led inexorably to where she sits holding the Baby on her knee. A benevolent brown cow looks admiringly over her shoulder as the first of the Kings kneels to kiss the outstretched hand of the Child. The colors are wonderful, they smolder on the canvas—the Virgin’s rich blue robe, the scarlet mantle of the second Magi, the crimson-and-gold brocade tunic of the third King.

I’ve had a crush on that King since I was sixteen. He is dressed in the height of fifteenth-century fashion, his full-flowing sleeves falling to mid-calf, his legs (a little thin, but not bad) encased in skintight hose. He has just swept off his cap to honor the Holy Family and his brown hair falls in wavy disarray over his forehead. If I ever saw a man who looked like that…

Suddenly I realized that I had seen a man who looked like that. No wonder the half-glimpsed profile of the man who (Gerda hoped) was following us had looked familiar. The same oblique shadows under the cheekbones, the same sharp angle of the jaw, the same indentation at the corner of the firm lips. What was more, I knew that man—or his double. A man I hadn’t seen for almost a year…

John had to jog my elbow before I noticed him. He begged my pardon in clipped idiomatic German and moved away, but not before I had seen his nostrils flare with annoyance. The conceited creature had expected to find me palpitating with girlish expectation, instead of intent on a work of art.

I followed him on a seemingly leisurely tour of the exhibits; actually it didn’t take more than ten minutes for him to reach the exit. Once on the street, he set a pace sufficiently brisk that I would have had to run to catch up with him, which, for a number of reasons, I was not about to do. Turning the next corner, he stopped at a parked car and unlocked the door. I arrived as he opened it; he stood back, motioning me in with a graceful bow. Perfect timing, as usual.