Martin must curb his jealousy when his classmate, Harper, appears in the school parade with an elaborate astronaut costume; and, imagining himself a space cadet, Martin uses his pogo stick to accidentally propel himself from his tree house.

Martin's back in two more stories. For their science fair project, Martin's team is going to help save the planet by organizing a beach walk. In the second story, Martin learns what it takes to score an A+ in teamwork and puts his knowledge of tools to good use as a volunteer at Bicycle Recycle.