Can Monk uncover the truth behind a deadly opium conspiracy?

When the body of a small-time crook named Mickey Parfitt washes up on the tide, no one grieves; far from it. But William Monk, commander of the River Police, is puzzled by the expensive silk cravat used to strangle Parfitt. How has this elegant scarf—whose original owner was obviously a man of substance—ended up imbedded in the neck of wharf rat who richly deserves his sordid end?

Monk is now a superintendent with the Thames River police and is struggling to earn the respect of his men.  While on patrol near Waterloo Bridge he notices a young couple at the bridge railing.  Are they embracing or is she pushed, as horrified, Monk sees the young woman fall to her death in the river.  With the help of Hester, the young mud lark  Scuff, Sutton the rat catcher and his dog, Snoot, Monk investigates more deaths and must race against time to prevent further tragedy...

Monk is commissioned to find the stolen ivory from the hold of Clement Louvain’s  ocean-going schooner.  The river Thames – ‘the longest street in London’- is new territory for Monk, and without the help of the River Police, he does not stand a chance of finding the thief, or even of keeping his own life.  Hester’s clinic admits a woman with a mysterious connexion to Louvain.  We meet, for the first time, the street-wise Cockney orphan, Scuff, who will feature more in the lives of Hester and Monk.

For the prostitutes of Leather Lane, nurse Hester Monk’s clinic is a lifeline, providing medicine, food and a modicum of peace.  However, the mysterious death of Railway magnate Nolan Baltimore in a sleazy neighbourhood brothel overshadows all else.  Meanwhile Monk acquires a new client, who asks him to ascertain whether her fiancé, an executive in Baltimore’s railway firm, has become enmeshed in fraudulent practices that could ruin him.  As Monk views the last railway tracks of a new line being laid, his past comes back to haunt him and warn him of a new tragedy about to unfold....

Hester serves as a volunteer nurse for Dr Kristian Beck, an intense Viennese émigré.  Beck’s wife, Elissa, is English but the two met during the 1848 revolution in Austria when both were freedom fighters.  When Elissa and another woman are found murdered in the studio of an artist, suspicion falls heavily on the doctor.  The social evils of gambling addiction and anti-Semitism are some of the unexpected results that come to light...

Monk agrees to attend a dinner party at the lush home of arms dealer Daniel Alberton, whose daughter is madly in love with the American Lyman Breeland, who wants to buy munitions for the Union Army.  But then the handsome Confederate Philo Trace appears on the scene and he just happened to have secured a deal with Alberton beforehand.  When Alberton is found murdered and his daughter has run off to America with Breeland, Monk and Hester follow only to find that they may be chasing the wrong suspect...

A young groom enlists private investigator William Monk to track down his fiancée, Miriam Gardiner, who disappeared suddenly from a party at a luxurious Bayswater mansion.  But Monk soon finds the coach in which Miriam fled and nearby, the murdered body of the coachman.  There is no trace of Miriam.  Monk and Hester, newly married, chase down the clues as to why Miriam would run away from a marriage that promised so much...

In a sensational breach of promise suit, two wealthy social climbers are suing on behalf of their beautiful daughter, Zillah.  The defendant is Zillah’s alleged fiancé, brilliant architect Killian Melville, who adamantly declares that he cannot and will not marry her.  Melville’s counsel, Oliver Rathbone, enlists the help of Monk and Hester and the court case ends in a tragic outcome that no-one could have foreseen.....