Louisa Evans rescues a sick man who comes stumbling to her door one night, and he turns out to be the Nicholas, Marquess of Overlea, a progeny of the family that ruined hers. Both of them feel the attraction, and they meet again when circumstances lead to Louisa seeking Overlea's help. Nicholas is in need of a wife, since his grandmother is adamant that he get married and get an heir on the way lest the title falls to his useless cousin (so few good cousins in Regency romances, let me tell you). The thing Nick didn't tell Louisa is that he is ill and his illness is genetic, therefore he plans to select someone else to be the father to their child.There is a secondary romance in development during this book that will likely be the subject of the author's next novel. It's cute, but doesn't really contribute anything to the plot.Things go pretty smoothly in the book, there are no major misunderstandings and fights among the two leading characters. There are some tongue-wagging about the speed of the marriage, but things go along well for the newly married couple; even the crotchety old Dowager Marchioness likes the lowly-born Louisa and her family.This was a very quick read for me, I finished it in around 2 hours. The plot is nothing complex, the mystery is not too deep. H/H are both reasonable, responsible people, who get along reasonably well and fall in love quickly without impediment (although of course, in typical Regency romance fashion, neither will actually say the L word to each other). The mystery is easy to solve, the book is an enjoyable, quick, very easy read.