The paperback editions of The Boxcar Children Mysteries: #13, Snowbound Mystery; #14, Tree House Mystery; #15, Bicycle Mystery; and #16, Mystery in the Sand are offered together in a cardboard case. About the Author Gertrude Chandler Warner grew up in Putnam, Connecticut. She wrote The Boxcar Children because she had always dreamed about what it would be like to live in a caboose or a freight car--just as the Aldens do. When readers asked for more adventures, Warner wrote more books--a total of nineteen in all. After her death, other authors have continued to write stories about Henry, Jessie, Violet, and Benny Alden, and today the Boxcar Children series has more than one hundred books.