With The Hollow Boy, new characters are introduced (or bumped off) as several storylines (two major cross-series arcs and a couple of smaller contained arcs) deftly interweave. We get more information about Lockwood's past, Lucy's abilities, and the strange goings-ons causing the hauntings. Tantalizing clues are dropped but honestly, Stroud so masterfully ratcheted up the suspense that this was definitely the most nerve-wracking volume of the series. Suitable for middle graders and up but with more than enough nuance and sophistication to greatly appeal to adults as well.
Story: Chelsea has become the scene of a huge outbreak of hauntings - causing the area to have to be cordoned off and attended to in great force by the various agencies. Although Lockwood is considered too small to be valuable, they will soon find themselves inexorably drawn into the mystery. Add in a wealthy benefactress, a parade and celebration party to keep the populace calm, and perhaps the scariest haunting of the entire series and Lockwood and Co will be very busy.
What the series has going for it by this third book is an incredible sense of world building. Although set in a modern, albeit alternate, London in which spirits of the undead run amok, there is an ethereal, almost fantasy-type setting where I picture the characters dressed straight out of a Dickensian tale. Like J.K. Rowling with the Harry Potter series, author Stroud smartly keeps so much of the worldbuilding timeless so readers can be transported to and fall fully under Lockwood & Co.'s gothic spell. You'll rarely read about Ipads, cell phones, internet, etc.
Less effective, though, was the addition of a new character to the team: Holly Munro. There are hints that she will have a larger role to play in the future (especially considering which agency she originated from) but for this book, she pretty much plays a foil to Lucy. Cue cat fights, jealousy, and far too much of Lucy mooning dreamily over Lockwood while competing with Holly for his attention. It was disappointing to read yet another middle grade book where the female characters can't work together and fight constantly over the males (I am reminded of the somewhat overt misogyny of Philip Reeve's Larklight series).
That aside, the characters are, as always, brilliant. From George to Lockwood to all the side characters, each is unique and comes with a firm perspective. Just by reading a line, it is obvious whose dialogue it is because each character has such a distinct personality. Add in the most developed character of all - London itself - and you get a book that really is a treat. In this case, a nail biter to the end.
I am greatly enjoying the Lockwood & Co. series. It's been quite awhile since a children's book series has been treated to such carefully crafted worldbuiling and characterization. I am very much looking forward to the next book in the series.
Note: I listened to the Audible version and the narrator did a decent job with the character and story.