The "Magic Tree House" series is a collection of books written by Mary Pope Osborne with titles that have at least two words that start with the same letter. These books follow the journeys of Jack and Annie as they travel through many different time periods.
Some titles of the books in the "Magic Tree House" series include "Dinosaurs Before Dark," "Night of the Ninjas", "Lions at Lunchtime," "Tonight on the Titanic" and "Dingoes at Dinnertime."
"Dinosaurs Before Dark" was the very first book in the "Magic Tree House" series. In this book Jack and Annie discover the tree house and use the magical books there to travel back to times when dinosaurs marched the earth 65 million years ago.
Ever since that book, Jack and Annie continued to use the Tree House and magical books to travel to other time periods such medieval times and the era of the Titanic. Mary Pope Osborne has published 52 books in the "Magic Tree House" series.
In addition to the "Magic Tree House" series, Mary Pope Osborne introduced the "Magic Tree House Fact Trackers". These non-fiction books are companions to the Magic Tree House series and teach about the history of the time period that Jack and Annie travel through. The companion to "Dinosaurs Before Dark" is titled "Dinosaurs."