An earl in disguise falls for the brilliant daughter of an impoverished baronet in Bennett's charming second Byronic Book Club Victorian romance (after Up All Night with a Good Duke). Spinster Lucy Bertram, 28, ghostwrites her father's scientific articles for the Linnean Society, a male-only group of scientists who court controversy in their support of Charles Darwin. When a patron of the society is murdered, Lucy's father is among the suspects and William Lockhart, Earl of Kyle and a spy for the Crown, disguises himself as a groom in the Bertram household to investigate. Drawn to Lucy's innocence and beauty, William agrees to help her find her older brother, Monty, who she believes now lives in a dangerous part of London and whose help she needs to avoid an unfavorable marriage scheme their father has cooked up. Meanwhile, William enlists Lucy's knowledge of botanical poisons to help unearth the killer, in exchange agreeing to a "courtship of convenience" that will free her from her undesirable suitor. Mystery and romance receive equal attention as the intense attraction between Lucy and William and their pursuit of the killer both heat up. Readers will cheer on this well-matched couple. Agent: Jessica Alvarez, BookEnds. (Feb.)