The self-proclaimed great-great-grandson of Sherlock Holmes helps Sergeant Gunther Wilson solve a number of different cases. Solutions for each mystery are given at the end of the book.
The spirit of a dead actress turns two children invisible and sends them out among a group of colorful street performers to search for a missing necklace.
While trying to get back at the girl who has stolen her boyfriend, sixteen-year-old Annie and her stepbrother Nick accidentally send threatening e-mail messages to a stranger and find themselves targets for a murderer.