Devil in Winter
The "reluctant hero" romance distilled to its essence. Sebastian St. Vincent, villain of the previous book, marries Evie Jenner in a marriage of convenience and is humanized by having to actually love someone. Kleypas writes his gradual transformation with real psychological intelligence; by the end, readers who despised him are weeping for him.
One book earlier Sebastian abducted the heroine's best friend for her dowry; here a wedding and a gunshot wound launder him in three hundred pages. Evie's stammer fades exactly as the plot stops needing it, and the club-management middle idles until a melodramatic villain wanders in to finish things. Redemption this efficient feels like bookkeeping.
The case for it and the rest of the canon open with Pro.
