The Somnambulist is reminiscent of Sherlock Holmes (the 2009 movie). That is, if you strip away the cute bromance and the innate charm of Robert Downey Jr. and Jude Law. Here Holmes is replaced with Edward Moon, a stage magician and amateur detective. His sidekick is the taciturn Somnambulist, a giant, hairless man who is rather like a human pincushion. Only in this case, replace "pin," with "swords."
The intro paragraph is both one of the best parts of the novel and unintentionally predictive of the story's quality: "Be warned. This book has no literary merit whatsoever. It is a lurid piece of nonsense, convoluted, implausible...frequently ridiculous and willfully bizarre."
It starts off well enough, with the murder of an obese actor, the perpetrators, his mother and a strange lizardlike being. Unfortunately, the protagonist, Moon, shows up and things get dull quickly.
Moon, I am told, is a brilliant man, possessing the kind of acumen one would expect from Sherlock Holmes. So I'm told. In reality, Moon mostly moons about, complaining that he is bored, and then when given a case to solve, approaches the task like a man going to the gallows. He and the Somnambulist wander about the city, doing very little to solve the crime. If this were a city like Mielville's New Crobuzon, the exploration of the streets might be fun. But this is London. Plain, old London. Beyond Moon's fascination with freak-show whores (a bearded lady), nothing in the first 160 pages is very imaginative.
Which, coincidentally, is as far as I read. So this is pretty much a DNF unless I find the time to skim to the end. For what it's worth, I don't really see this as steampunk per say. More like fiction set in the Victorian era with a few occult elements. But it lacked the strong sense of otherness and paranormal technology that I'd expect in steampunk.