A mathematical model is proposed for interpreting the love story between Elizabeth and Darcy portrayed by Jane Austen in the popular novel 'Pride  and Prejudice'. The analysis shows that the story is characterized by a sudden explosion of sentimental involvements, revealed by the existence of a  saddle-node bifurcation in the model. The paper is interesting not only because it deals for the firts time with catastrophic bifurcations in romantic  relationships, but also because it enriches the list of examples in which love stories are described through ordinary differential equations.