From the back of the book:
Henry, Jessie, Violet, and Benny used to live alone in a boxcar. Now they have a home with their grandfather and are spending the summer out west on Mystery Ranch.
The excitement begins when they meet their old friend, Mike. When Mike is blamed for starting a fire, the Boxcar Children know he's innocent. But can they discover who's
really behind Mike's Mystery - before it's too late?