This elusiveness is all the more alluring given that twenty-second-century researchers have access to a mountain of detail—the ephemera of our digital lives, preserved in Nigerian data centers. “We have robbed the past of its privacy,” Tom recalls his dean saying. Tom knows Francis’s favorite snack (an apple), has scanned Vivien’s browsing history, and can watch “the daily news that troubled her contemporaries, the diverting scandals, the ancient sporting triumphs.” Much of the novel’s charm lies in its re-creation of our era as seen from the future. (A luthier’s fortunes improve after he meets “a member of the famous group Radiohead.”) A hopeless nostalgist, Tom rhapsodizes about the glories of 2010, the effect at once amusing and chastening. “To have been alive then in those resourceful raucous times, when the sea stood off at a respectful distance, when you could walk in any direction as far as you liked and keep your feet dry,” he laments. The air was “purer and less radioactive” then; the average life span had not yet dropped to sixty-two. For McEwan, whose tone often tends toward the elegiac, Tom is a useful self-deprecation, and a didactic mouthpiece: Readers, he seems to say, appreciate what you have.