Don Tillman and Rosie Jarman are now married and living in New York. Don has been teaching while Rosie completes her second year at Columbia Medical School. Just as Don is about to announce that Gene, his philandering best friend from Australia, is coming to stay, Rosie drops a bombshell: she's pregnant.
In true Tillman style, Don instantly becomes an expert on all things obstetric. But in between immersing himself in a new research study on parenting and implementing the Standardised Meal System (pregnancy version), Don's old weaknesses resurface. And while he strives to get the technicalities right, he gets the emotions all wrong, and risks losing Rosie when she needs him most.