In 1872, the area of London known as Lambeth Marsh, along the bank of the River Thames, just across from Westminster, was a dark and dangerous place.
It was full of narrow streets of poor houses. It was a violent place, with pickpockets and thieves waiting to rob and steal, and no honest man ever admitted to visiting it.
This was the London that Charles Dickens wrote about in Oliver Twist; his characters Fagin, the pickpocket, and the criminal Bill Sikes would probably have felt quite at home if they had visited Lambeth Marsh.