Our 7-year-old grandson had asked for more Stink books for Christmas, so we gave him two. "The Stink: Solar System Superhero" was a big hit with him. The story line is fun to follow, and, along the way, the author slips in lots and lots of facts about the solar system. Since our grandson has been studying this topic this year, he was extra interested in this story. It's an appropriate length that can be read in multiple sessions for this age.