Just when Josh starts to think his break from school is going to be all chores and no cheer, his best friend, Mark, invites him to spend their break helping restore a historic home and mill in Oregon. With the help of their friends Angela and Mary Jane, and under the watchful eye of Aunt Sue and Uncle Doug, the kids spend weeks fixing up the grounds, basking in the freedom of country life and learning about the surrounding area Not to mention eating bugs, domesticating feral cats and starring in a movie! But it's not all fun and filming. The mill is in financial trouble, and the kids have to figure out a way to help Aunt Sue and Uncle Doug keep it running, in spite of it being haunted.
The Ghost of Mill House follows Bus to the Badlands, where we first met Josh and his classmates.