Thomas rocks his fourth Victorian thriller set in 1885 London, a pairing of inquiry agent Cyrus Barker and Thomas Llewelyn in yet another complicated case of murder and mayhem. The Thames Police have recovered a barrel containing the decomposing remains of an Italian assassin and his wife.

Both Scotland Yard and the Home Office are currently swamped with the crimes that plague the city, so it is natural that Barker would be tapped for the new threat, especially with the discovery of yet another body: a wealthy man found in the park, a sharp object inserted through his ear and into his brain. The connections are too obvious to ignore with the Sicilian Mafia making a power move in the city: “The presence of the Sicilian mob would alter crime in London forever.”

The advantage for Barker is his use of unconventional methods and infinite contacts throughout London in law enforcement and within the criminal element, the movers and shakers of that subterranean society. Sidekick Llewelyn is devoted to his boss, eager to learn from Barker as he assists in every aspect of a troubling and convoluted investigation.

Random assassins roam the city. Newly arrived from Sicily, brutally efficient Mafia henchmen attack victims in broad daylight. Barker and Llewelyn make critical distinctions between the Italians and the Sicilians, between the Sicilians and the Mafia, the hallmark of their organization the “Black Hand.” When various targets receive notes using this distinct signature, each is threatened very specifically to back off the case. Those who refuse are attacked.

One such victim is an Italian import from Paris trained in a relatively new investigative technique, the Bertillon System, which uses photographs and precise measurements to match known criminals to identity cards painstakingly created by specially-trained officers. The practicalities are challenging, and this method will soon bow to the more adaptable system of fingerprinting that is now universally accepted.

The characters are as colorful as the era. Various groups fight for dominance on the docks - free-roving street gangs, assassins, five French brothers with a stake in the outcome, and a Sicilian mastermind determined to take advantage of this opportunity to establish a foothold in London.

Barker is badly outnumbered by an enemy that blends easily into the population, assembling an uneasy alliance of street gangs, dock workers and others for a final confrontation that promises to engulf the wharf in violence. Training in the art of the dagger, Llewelyn, if nonplussed by the impending battle, is adamant in his determination to protect his mentor from harm.

From the first gruesome chapter when the two bodies are discovered on the Thames to the rollicking conclusion, fists and daggers flying, Thomas takes his intrepid protagonists on another wild adventure, filled with eccentric characters, plot twists and surprises, the accompanying historical detail impressive. We need never worry that Barker will fail to prevail: it is the journey, after all, that provides all the thrills along the way.