The Barrister and the Letter of Marque

As a barrister in 1818 London, William Snopes is a strong advocate who chooses to defend the poorer classes against the powerful. That changes the day a struggling heiress, Lady Madeleine Jameson, arrives at
his door. 

In a last-ditch effort to save her faltering estate, Lady Jameson invested in the acquisition of a merchant brig, the Padget, allowed by a letter of marque from the king's regent to legally capture cargo from French traders operating illegally in the Indian Sea. Yet when the ship returns to the London harbor, it's met by constables and soldiers ready to seize its goods, accusing the sailors of piracy. And the letter proving their legality has disappeared. 

Moved by the lady's distress, intrigued by the claimed letter, and goaded by an opposing solicitor, William Snopes cautiously takes the case. But as he gets deeper into the mystery and prepares for trial, he learns that the forces arrayed against Lady Jameson, and now himself, are even more powerful than he'd imagined.