If someone was forced to describe The Creeping Shadow with one word, it would be reconciliation. The Creeping Shadow is, in many ways, a novel about how Lucy reconciles with some of her best friends in the world in Lockwood and Co. after she has a falling out with them. Throughout the novel, Lucy takes steps to reconnect with people who she loves and cares about. And in the end, she is successful: she grows close once again to her friends and they continue their business in Lockwood and Co. together. In that sense, despite the horror and supernatural happenings that go in The Creeping Shadow, Stroud's novel is a hopeful one that stresses the power and importance of having a close group of friends.
At the start of the novel, readers learn that Lucy has left Lockwood and Co., the agency of which she was a founding member. To earn a living and stay busy, Lucy has decided to go into the freelance paranormal investigation/spirit fighter business. And she is a freelancer in every sense of the word: she works for whatever agency (and person) needs her assistance—even agencies she had sworn off.
First, Lucy's help is requested in the case of a woman named Emma Marchment, an evil woman who is now a ghost. To destroy Mrs. Marchment's ghost, she receives help from the Rotwell Agency. But she doesn't particularly like the Rotwell Argency as Lucy thinks they are useless. Unlike everyone else, though, Lucy has the all-powerful Whispering Skull, whose help she enlists to defeat Marched's ghost and uncover the Source —a Source that nearly kills her.
Over time, the Rotwell agency grows increasingly angry with Lucy. They order Lucy to destroy the Source (a mummy's head) in the infamous Fittes Furnance, where all Sources are destroyed. At the Fitters Furnace, the Source's connection to the world is severed and the danger it poses is reduced significantly. Without destroying the Source, Lucy's agency says, she will not be paid for her work in the Marchment case. Lucy realizes that she has no choice in destroying the Source, so she goes to the furnace and gives the Source to an employee, who promptly destroys the Source. That employee, however, also attempts to steal Lucy's Whispering Skull.
Lockwood enlists Lucy's help once again and asks her to join Lockwood and Co. again as a consultant. And together with her former agency, Lucy begins to investigate spirits around the city—just like they once had. Along the way, Lucy and her friends come face-to-face with participants in the black market, who don't take too kindly to Lucy and her enterprising ways. They also come head-to-head with a ghost who is an informant, a Spirit Cape with magical powers, and two strange mysteries involving two people: Steve Rotwell and Penelope Fittes. But in the end, the Whispering Skull tells Lucy something important: that Penelope Fittes is not who she claims to be. She is a woman named Marissa.
Unlike many other novels written for teenagers, The Creeping Shadow is a thematically complex and rich book. It assumes that its readers—which are made up of teenagers and young adults—are fully capable and intelligent people. It explores themes of the power and importance of friendship, reconnection, and the danger that the supernatural and supernatural beings pose. Additionally, it explores themes of mystery, love, and how friends will be deceitful to the people they like.
Above all, The Creeping Shadow is a novel meant to entertain its readers. The novel is well-written and is propulsive in its energy. There is never a dull moment in The Creeping Shadow; Stroud designed his book in that way. Tonally, Stroud's novel is mysterious, tense, intense, propulsive, violent, and perhaps most significantly, compassionate.
