Frank and the Future of Mars tells the Martian adventures of twelve-year-old Frank Wilson, in the year 2185. Frank lives in underground Saganville on Mars where his parents are gardeners. Frank must choose his life work. His father expects him to choose gardening, but Frank wants to try other occupations. He sneaks out of Saganville illegally, by himself, to look for diamonds in a crater on Mars. He discovers that diamonds are not important on Mars, so Frank changes his quest to find rare, Martian limestone. Failing to find limestone, Frank faces trouble from three boys in his class, from a friend's sister using blackmail against him, and a father who grounds him. Frank and his friends try to plant wheat.

After his initial failures, Frank is determined to try again, with different tactics and struggles to do something to make his parents proud of him.