Penrose, Andrea. Wrexford & Sloane historical mystery

Sequel to: Murder at Half Moon Gate

Charlotte Sloane's secret identity as the controversial satirical cartoonist A.J. Quill is safe with the Earl of Wrexford, but sharing the truth about her background has cast shadows on their relationship. When her cousin is murdered and his twin brother is accused of the crime, Charlotte turns to Wrexford for help in proving the young man's innocence. Determined to track down the real killer, their investigation leads them on a dangerous chase through Mayfair's glittering ballrooms and opulent drawing rooms. Was her cousin murdered over a romantic rivalry, or staggering gambling debts? Or could the motive be far darker and involve the clandestine scientific society that claimed both brothers as members? -- adapted from jacket