Cressida is a woman who has everything. A fulfilling job, two adorable children and Harry, who is a wonderful husband and father. It sounds like the perfect life - but is it? Cressida is having a hopeless, passionate affair with Tom, a serial philanderer. Now she is pregnant. And it's not just Cressida - the whole world seems to be dangerously fertile. Tom's partner Nita announces that she, too, is expecting another baby. Then there's Cressida's GP, Margaret, single and desperate for the child she thinks is her due, and Sophie, Harry's secretary, so baby-hungry that she is prepared to go to any lengths to conceive. In the well-ordered world to which Harry and Cressida feel they rightfully belong, things will never be the same again. But then, when babies are concerned, are they ever?