Big Ben chimes in the first seconds of the first day of 1900, the start of a fresh century. Inside London's oldest gaol, preparations are afoot to hang Victorian England's deadliest assassin, a man wanted for two decades' worth of murders. Cold-blooded killer Simeon Lynch has lived a brutal and glorious life in the employ of the House of Moriarty - the most feared criminal enterprise in the world. Now, as he faces the noose, Simeon learns dark truths about his master, about Sherlock Holmes and about his own past. Truths that make him determined to escape and kill again... Follow Simeon's bloody footsteps through the capital's cobbled alleyways, wretched workhouses and flash taverns as he crosses swords with Sherlock Holmes and the villainous characters of Victorian London.