Lockwood & Co. is a ghost-hunting agency in futuristic London, about 50 years into when everyone calls The Problem. Basically, The Problem is that ghosts have starting coming back every night with a vengeance. And the only ones who seem to be able to sense the presence of or see ghosts are children. By the time children become grown ups, they are unable to see them or sense them as well any more, so it is children who work as ghost hunters for adult supervisors.
At the beginning of The Screaming Staircase by Jonathan Stroud (Lexile: 720; Interest Level: Grades 4-8), Lucy's supervisor chooses not to listen to her warning during a mission, and things go terribly wrong. So Lucy heads to London to search for a new job, getting hired by Anthony Lockwood in an agency with no adult supervisors. Lucy, George, and Lockwood (as he prefers to be called) enc0unter a pretty spooky ghost who leads them into a mystery that is a half-century old and an estate that has be haunted for about 500 years. Filled with ghosts, humor, mystery, adventure, and even the sarcasm Jonathan Stroud is known for, The Screaming Staircase is one of the better horror stories I have read in a while. Warning: it may take a little while to get into it, but I promise, the ending will NOT disappoint! (390 pages)
One of the reasons I became an elementary school librarian is so I can read children's books.