“So the idea was to break the series in two to make that clearer.” Now instead of being numbered chronologically from one to 56, the beloved books chronicling the adventures of time-traveling siblings have been split into three separate but related lines: the classic adventure books (previously one to 28), the Merlin Missions (previously 29 to 55), and the nonfiction Fact Trackers, which act as companions to their fictional counterparts. “The Merlin Missions were longer, more complicated books aimed at children who were reading at a third grade level,” explains Mallory Loehr, senior vice president and publisher at Random House Children’s Books. Along with the new look, the publishing house wanted to clarify the difference between the classic adventure books and the Merlin Missions titles. Her first thought: “This was going to mean a lot of work for librarians to reorganize these books!” That wasn’t the publisher’s intent. She also noticed the book’s number-#29-the same one as Christmas in Camelot, an older title in the series. Shoemaker, the librarian for Mill Road Primary School in Red Hook, NY, spotted when she saw the latest addition, A Big Day for Baseball, at a Barnes and Noble.

But that’s not the only thing that Barbara J. Publishing houses often reissue older titles with new covers, and Mary Pope Osborne's “Magic Tree House” series, celebrating its 25th anniversary this year, is no exception.

Magic tree house by mary pope osborne