A Sunless Sea by Anne Perry

A Sunless Sea: A William Monk Novel - Someone killed Zenia Gadney and left her body on Limehouse Pier.  Because the murder was very gruesome, it has scared the public and politicians are wanting a quick arrest and trial.  All the evidence point to Dinah Lambourn, widow of Dr. Joel Lambourn who was found two months earlier with his wrists slit in a nearby park.  Dinah insists her husband was murdered because of his research into the packaging of opium that he was doing for the government.  She also claims she is innocent of Mrs. Gadney's murder.  Monk and Hester follow every lead possible to find the truth of both deaths.  Oliver Rathbone agrees to defend Dinah and finds his efforts thwarted at every turn.