The Creeping Shadow, by Jonathan Stroud, is the fourth book about Lockwood and Co., about a group of kids fighting malevolent ghosts in an alternate England where the dead have become a serious problem. If you loved the first book, and why would you not, because it is excellent, but found books 2 and 3 somewhat less engrossing, do not let that stop you from reading The Creeping Shadow!
All that made the first book good is here as well--the hair-raising psychic investigations, including some really horrible ghosts, interesting dynamics between the team members that don't slow down the narrative, and solid world-building. Here in the forth book, as an added bonus, there begins to be some actual progress on understanding why problem of ghosts happened to begin with, which makes it an even more interesting read.
At the end of book 3, Lucy left Lockwood and Co. to work on her own, which was a real downer of ending. Happily, she rejoins the team in The Creeping Shadow, and her time on her own offers the opportunity see the other members of gang--Lockwood, George, and Holly, with fresh eyes. The first ghost they tackle when they are once more together is really really gruesome--he was a cannibal murderer, and if you are squeamish about ghostly body parts, be warned! I don't generally like horror qua horror, but I was utterly gripped.
So gripped by the whole book, in fact, especially once Larger Elements of the Problem began to unfold, that I stayed up past my bedtime to read it all in a single sitting. The only downer--it ends with a teasing note--not quite a cliffhanger, but awfully near the cliff's edge, and I want the fifth book Now.
side note--I am now totally shipping George and Lucy. Although the Skull comes to life as more of a person in this book, and his ambiguous, trickster personality is not as unappealing as one would expect from an evil (?) bottled skull......
disclaimer: review copy received from the publisher for Cybils Awards judging