So let's start with the end - the author informs us that he tweaked characters and history a wee bit to make this story work. As it's a historical fiction kind of book, I doubt anyone reading that kind of book is going to mind much. It works. Nothing about the tweaks are so shocking that you'd going to say "Wait a minute that person / place / action / word seems out of place".
That said, this is the story of Dodger, not his real name, but his real name is not pleasant to him and still isn't likely his real name. Dodger is a young lad just trying to get by in Dickensian London -- literally, he ends up hanging out with Charlie. Thing is, Dodger got his name by, well, dodging things - being quick. Everyone knows Dodger, everyone in his little section of London anyway. Dodger knows all of the rules namely that you don't see nuthin, you don't hear nuthin, you don't know nuthin.
Dodger had the misfortune of witnessing something happen to a girl that he simply could not ignore, some things you do see, no matter what the rules say. Dodger becomes unusually attached to the girl. Just knowing that she is okay isn't enough for the young chap, someone should pay for this - too many girls end up like her, but this time there was a witness and there are clues. He starts asking a lot of questions, bringing a lot of attention to himself and his streets, making his neighbors nervous. Still, Dodger knows that somehow he has to find the bad guys, save the girl, not ruin his own rep in the process, and oh yeah -- survive it all.
We follow Dodger through the streets of London. Into the sewers. We meet the rich, the poor, the barbers, the famous, the not so famous, the killers, the saviours -- sometimes they're more than one of these things.
The only thing holding me back from giving this 5 stars is that the actual story and characters seem lost at times in the story that is the city. It's fine to write a "love letter" to a place or a time period, but when doing so in a fictional story, don't let that overpower your characters and your story.