By Wendy Mass
A brother and sister find a mysterious bag in their yard that pulls them back in time, straight into a hunt for a missing sword.
Chase and his younger sister Ava find an old leather bag sitting in their yard, and the moment they look inside, it whisks them into the past. They land in a faraway time where a sword has gone missing and someone needs their help to get it back before the wrong hands keep it. The two of them have to work together, use what's in the bag, and find their way home again. It's a brother and sister on an adventure neither of them planned, which is a big part of why it lands for a Magic Tree House fan.
If what your child loved about Magic Tree House was Jack and Annie, a brother and sister figuring things out side by side, this is the closest match on the shelf. Wendy Mass gives them the same setup, an everyday object that turns out to be a doorway through time, but the books are made for a newly independent reader, with a color picture on nearly every page and short chapters that keep the story moving. This is book one, so a stack more waits if it clicks.