"The Rosie Effect" by Graeme Simsion is a heartwarming and humorous continuation of the story of Don Tillman, a socially challenged genetics professor, and his wife Rosie Jarman. After successfully navigating the complexities of their relationship in the first book, "The Rosie Project," Don and Rosie are now married and living in New York City.

But their happily ever after takes an unexpected turn when Rosie announces that she is pregnant. Don, who thrives on routines and order, struggles to handle the chaos and uncertainty that comes with impending fatherhood. Determined to be the perfect father, Don dives into research and starts making plans that he believes will guarantee a successful pregnancy.

However, Don's well-intentioned actions inadvertently create misunderstandings and strain in his marriage. As he becomes consumed with his mission to ensure the best outcome for his baby, Don finds himself drifting further away from Rosie. With his social ineptness and lack of emotional understanding, Don unwittingly creates a series of comical and often disastrous situations.

As the pressure builds, Don realizes that he needs to step back and reassess his approach to fatherhood and his relationship with Rosie. With the help of his loyal friends, including his unconventional therapist Gene and his former colleague Claudia, Don embarks on a journey to become the partner and father Rosie needs him to be.

"The Rosie Effect" is a charming and insightful novel that explores the challenges of marriage, impending parenthood, and the importance of embracing unpredictability in life. With his quirky and endearing protagonist, Graeme Simsion delivers a story filled with humor, compassion, and a deep appreciation for the power of love and acceptance.