This is a companion story to Life as We Knew It. It takes place in NYC, harder hit because of being on the coast, but better off in some ways because it's a city and not as remote as the country towns of Pennsylvania. Pfeffer manages to create another compelling story instead of just retelling the same events happening to different people. It's not necessary to read LAWKI, because it's not a sequel at all, but it makes it more interesting. I would recommend it to fans of LAWKI as well as people looking for a good "the world is ending" book.