Nicole Krauss's elegant, haunting debut, Man Walks into a Room, is a what-if novel. What if, asks Krauss, a man woke up one day and he'd forgotten everything he knows? Samson Greene is found lost in the desert near Las Vegas, memory-less thanks to a tumor "applying its arbitrary, pernicious pressure to his brain." Once the tumor is removed, he can remember his childhood up until his 12th year, but then all is blank. He returns to New York, to his wife Anna, to his life as a Columbia University English professor, but none of these things makes sense to him anymore: "Samson could dredge up no feeling for his own life but that of vague admiration." When he receives a call from a mysterious scientist inviting him back to the desert for a sinister-sounding memory experiment, Samson heads West with a kind of despondent fatalism. Krauss's novel moves gracefully from exploration of a lost soul to science fiction to a meditation on memory. If the book unravels a bit at the end, it's only because Krauss is trying to do too much--certainly no literary sin. --Claire Dederer