A Lady of Conscience by Mimi Matthews

A Victorian bluestocking with a passion for lost causes attracts the unwilling attention of a frost-hearted viscount during her tumultuous debut season in Bath in USA Today bestselling author Mimi Matthews’s fifth book in her acclaimed Somerset Stories series.
West Country beauty Hannah Heywood may be quiet with fashionable strangers, but when it comes to animals in need, she has no trouble finding her voice. Newly arrived in Bath for her very first season, all she desires is to find one like-minded gentleman. A man of warmth and compassion, as sensitive to animals as he is to people. But if such a man exists, he dare not approach her. Not with the tall, blond, and menacing Viscount St. Clare standing in the way.
James Beresford, Viscount St. Clare has often been described as a sentient block of ice. A man so cold and dispassionate, he would never suit a young lady of Hannah’s disposition. And she would certainly never suit him. Focused on repairing his family’s infamous reputation, James requires a diamond of the first water. The daughter of a duke or a marquess, at least, not a simple country girl with a passion for four-legged creatures.
And yet, there’s something about conscience-driven young Hannah that draws James, first to Bath, and then into one increasingly hare-brained scheme after another. She confounds him at every turn, subverting his expectations and threatening to do what no lady has succeeded in doing before—thawing his ice-cold heart.