Why would anyone break into a bookmobile—but take nothing?
One night, Cindy, Jay, and Dexter see a flickering light in the window of the library's bookmobile—is it a ghost? No, it's a break-in. Someone is looking for a secret among the stacks and it's up to the Spotlight Club to figure out the truth.

There is no shortage of suspects: P. Nelson Edward, who says he doesn't know Olga Ratchett, but he does. Olga Ratchett, who is clearly angry with P. Nelson, but why? Why is she so upset about the bookmobile being closed early? And who is the mysterious man with the silver cane?

Another mystery needs solving. The Spotlight Club is on the case!