Carolyn Keene

The Mystery of the 99 Steps is the forty-third volume in the Nancy Drew Mystery Stories series. It was first published in 1966 under the pseudonym Carolyn Keene. The actual author was ghostwriter Harriet Stratemeyer Adams.

The Mystery of the Brass Bound Trunk is the seventeenth volume in the Nancy Drew Mystery Stories series, published under the pseudonym Carolyn Keene. It was first published in 1940 by Grosset & Dunlap.