Sometimes—perhaps only for an instant—we fail to recognize a companion; for a moment their identity ceases to exist, and thus we come to doubt our own. The effect is at its most acute in a couple, where our existence is given meaning by our perception of a lover, and theirs of us. With his astonishing skill at building on and out from the significant moment, Kundera has placed such a situation and the resulting wave of panic at the core of his new novel. In a narrative as intense as it is brief, a moment of confusion sets in motion a complex chain of events which forces the reader to cross and recross the divide between fantasy and reality.