In the early nineteen-eighties, the French artist Sophie Calle, who is known for projects that involve immersing herself in the lives of strangers or allowing strangers a view of her own life, found an address book on the street in Paris. Before mailing it back to its owner—a filmmaker called Pierre D.—she photocopied the contents and then proceeded to call each person listed in it to ask questions about him. “I will try to discover who he is without ever meeting him, and I will try to produce a portrait of him over an undetermined length of time that will depend on the willingness of his friends to talk about him—and on the turns taken by the events,” she wrote. She turned her encounters into short pieces, which were published almost daily over the course of a month in the newspaper Libération. When Pierre D. discovered what Calle was doing, he threatened to sue her for invasion of privacy, and she agreed not to re-publish the work until after his death. Siglio Press has just brought out the project—consisting of Calle’s writings and accompanying photographs—as a book, giving readers the chance to peer, along with Calle, into the touchingly elusive figure at the center of her investigations.