Nancy and her boyfriend Ned visit Coffin Hall to research the library's rumored ghost, but when a fire breaks out and Ned is blamed, it is up to Nancy to find the true culprit.

"Mr. Quisling is definitely up to something mysterious, and Emily and James are on high alert. First, there's the coded note he drops at a book event. Then Emily and James uncover a trail of encrypted messages in books by Mark Twain hidden through Book Scavenger. What is most suspicious is that each hidden book triggers an arson"--OCLC.

In 1904, eleven-year-old Suzanna is delighted with her grandmother's invitation to spend time in Boston and thrilled to help her famous uncle investigate a series of arsons, but much less pleased to be enrolled her in Miss Lydia Doucette's Academy for Young Ladies.