Sometime in the middle of March-the date could never be reliably established-he vanished. Even Monsieur Laval could not be certain of the departure date, because he was informed after the fact by a woman in Paris who claimed to be the gentleman’s personal assistant. Though two weeks remained on the lease, the handsome tenant did not embarrass himself, or Monsieur Laval, by asking for a refund. Later that spring, when Monsieur Laval visited the villa, he was surprised to discover, in a crystal bowl on the dining room sideboard, a brief thank-you note, typewritten, along with a hundred euros to pay for broken wineglasses. A thorough search of the villa’s stemware collection, however, revealed nothing was missing. When Monsieur Laval tried to call Jean-Luc’s girl in Paris to return the money, he found that her telephone line had been disconnected.

ON THE FRINGES of the Borghese gardens there are elegant boulevards and quiet leafy side streets that bear little resemblance to the scruffy, tourist-trodden thoroughfares of the city center. They are avenues of diplomacy and money, where traffic moves at a nearly reasonable speed and where the blare of car horns sounds like a rebellion in distant lands. One such street is a cul-de-sac. It falls away at a gentle pitch and bends to the right. For many hours each day, it is in shadow, a consequence of the towering stone pine and eucalyptus that loom over the villas. The narrow sidewalk is broken by tree roots and perpetually covered by pine needles and dead leaves. At the end of the street is a diplomatic compound, more heavily fortified than most in Rome.

Survivors and witnesses would recall the perfection of that late-winter morning: bright and clear, cold enough in the shadows to bring on a shiver, warm enough in the sun to unbutton a wool coat and dream of an alfresco lunch.