Otto and Leni thought they were safe: They escaped, barely, from war-torn Europe and are living as refugees in England. But now, the Crown has recruited them: Great Britian wants them to go back. As spies! Dropped behind enemy lines, they embark on a top-secret operation. Code name: Wolfsangel. Their mission? Capture the one person who can defeat the ultimate evil of Nazism! Der Fuhrer has destroyed Otto's and Leni's families, but what if the tables...

The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system!
When Jack and Annie got back from their adventure in Magic Tree House #23: Twister on Tuesday, they had lots of questions. How do tornadoes form? What kinds of tools can help predict bad storms? Where did the biggest snowfall on record happen? How fast are hurricane winds?
Did you know that there’s...

The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system! Getting the facts behind the fiction has never looked better.
Track the facts with Jack and Annie!
 
When Jack and Annie got back from their adventure in Magic Tree House #8: Midnight on the Moon, they had lots of questions. How did the universe begin? How long does it take to get to the moon?...

The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system! Getting the facts behind the fiction has never looked better.  Track the facts with Jack and Annie!!
 
When Jack and Annie got back from their adventure in Magic Tree House #4: Pirates Past Noon, they had lots of questions. Did pirates really make people walk the plank? What was life...

The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system! Getting the facts behind the fiction has never looked better.  Track the facts with Jack and Annie!!
 
When Jack and Annie got back from their adventure in Magic Tree House #3: Mummies in the Morning, they had lots of questions. Why did people make mummies? What was the mysterious writing...