Why things don't work

Carrie and her cousin Matt set out to rebuild her uncle's old race car and, as they work, discover the science that makes the car run.

A comic-book-style story in which Tom and Katie find Tom's grandfather's old motorcycle in a barn and troubleshoot and repair its problems one by one.

Annie and Ed work to rebuild a dismantled helicopter at her cousin's farm and, in the process, discover the science that makes helicopters fly.