Recommended by a friend, I enjoyed The Screaming Staircase quite a lot. The setting of this alternate London is similar to our own, but coloured by the supernatural in a way familiar to fans of the Bartimaeus trilogy - which I read ages ago but remember fondly. Not only do the trio of Lockwood & Co. have to deal with the unquiet (and often grotesque and violent) dead, but also the political machinations of the British gentry and the attempts of rivals to close down their agency. The story progresses like a horror-filled Sherlock-esque mystery, and the ending is incredibly satisfying.

What i enjoyed: the mystery is tied into the plot quite nicely and the transitions flow very smoothly, making it easy to want to keep reading and play along with the characters. Twists and surprises aren't jarring and can be figured out, but its still subtle enough to be enjoyed.
What I didn't enjoy: the characters didn't always seem like real people and it's a bit obvious that Lockwood is supposed to be like Sherlock Holmes. Despite the set up for the setting and age of characters it wasn't quite played right to feel like it was actually an alternative world where children were the heroes. Some events that should have had consequences didn't and vice versa. One major thing that granted on me the more it kept happening was how one main character has different strengths and weaknesses than the other 2, but is always described as incompetent and fat and it's outright stated as well as implied that him being fat is part of why he's incompetent and inferior to his peers. The other characters get plenty of descriptors and traits, but all he gets is various ways of saying he's fat and inferior. 
Overall though, it was an enjoyable read!