Grierson, Edward. A Crime of One's Own (New York: Berkley Medallion, 1969, c1967) 175 p.

The back room of a large urban bookstore is used as a subscription library. The library is run by Miss Monica Ferguson and Rita Preedy. It is very popular but lately strange things have been happening. Books are being defaced. Rarely used books are being checked out repeatedly. The bookstore owner is convinced there are spies exchanging messages in his store.