Solid romance, great characters, the plot is a bit implausible but works OK.
Male lead: Cain, the Marquess of Chase, uninterested in women, but this one catches his eye. He starts out wanting only a casual dalliance but then wants more.
Female lead: Juliana Merton, widowed in the opening pages, by the mysterious death of her husband, intent on keeping the bookseller's shop open.
The plot: First we find out about Cain's past, then Juliana's, repeat. The two fall slowly in love. The finale is the classic 'foil the bad guys and find true love.'