Grace is going to save the planet; well, at least she's going to try! It all starts when Miss Lois asks the third graders to work in groups to come up with ideas for how to "go green." The ideas start to flow: from turning off the lights, conserving water, and recycling, to decorating plastic bottles and holding a yard sale. At the same time, Mimi's older cousin comes to visit, and trouble comes along with her. As Grace becomes concerned about pollution and what kids can do about it, readers will be presented with enthralling facts; for example, it takes about 500 years for a plastic bottle to break down. Readers will also start thinking about how they can go green, too.