"At one point they tried to calculate when time began, when exactly the earth had been created," begins Time Shelter's enigmatic narrator, who will go unnamed. "In the mid-seventeenth century, the Irish bishop Ussher calculated not only the exact year, but also a starting date: October 22, 4,004 years before Christ." But for our narrator, time as he knows it begins when he meets Gaustine, a "vagrant in time" who has distanced his life from contemporary reality by reading old news, wearing tattered old clothes, and haunting the lost avenues of the twentieth century.In an apricot-colored building in Zurich, surrounded by curiously planted forget-me-nots, Gaustine has opened the first "clinic for the past," an institution that offers an inspired treatment for Alzheimer's sufferers: each floor reproduces a past decade in minute detail, allowing patients to transport themselves back in time to unlock what is left of their fading memories. Serving as Gaustine's assistant, the narrator is tas