A Lark's Release: A Regency Cozy (A Verity Lark Mystery #4)
Lynn Messina

And then of course there are the shooting lessons she has promised to give to the Duchess of Kesgrave. Verity has spent three months cruelly mocking the former spinster for her investigative pretensions, and now she is obligated to teach the woman how to fire a deadly weapon.
It is madness!
Thank goodness she stumbles onto a forged antiquities ring when she visits the British Museum with Hardwicke. Finally—something benign to focus her brain on.
Alas, when a murderer strikes close to home, threatening every member of her household, Verity realizes just how grossly she misunderstood the situation. Far from harmless, the counterfeit scheme is in deadly earnest, and now she must figure out the identity of a ruthless enemy who doesn’t care whom he hurts in his quest to eliminate her.
Welcome to the fourth installment of the Verity Lark Mysteries, where secrets run deep, and every move could be her last.