Until a year ago, forty-one-year-old geneticist Don Tillman had never had a second date. Until he met Rosie, ‘the world’s most incompatible woman'. Now, living in New York City, they have survived ten months and ten days of marriage.

But though Rosie has taught him the joys of unscheduled sex and spontaneous meal-planning, life is still not plain sailing for Don. Not least with the sudden arrival of his best friend Gene, serial philanderer, who takes up residence on their sofa.

Then Rosie drops the mother of all bombshells. And soon Don must face her hormonally induced irrational behaviour as he prepares for the biggest challenge of his previously ordered life — at the same time as dodging deportation, prosecution and professional disgrace.

Is Don Tillman ready to become the man he always dreamed of being? Or will he revert to his old ways and risk losing Rosie for ever?