BioFables: Book 4, Series 1Ages 10-adult Seven-year-old Mallory learns that taking a nine-pound rock from a public park is a lot different from collecting a few pebbles or stones. His twin sister, Melody, doesn't think it's such a big deal, but apparently everyone else does. Mallory and his Dad travel back to the Indiana Dunes both to follow up with the local police sergeant on the lost item that Mallory found and also to fulfill Mallory's hour of public service to settle his debt for removing the rock from the park.Mallory learns about fossils, the Great Lakes, glaciers, and the inland sea that covered this area from Mrs. Anna Graham, an elderly, long-time resident. She admires Mallory's rock, understanding its attraction to a little boy. Mallory's father and the police sergeant finish their discussion and head back to the police station with Mallory and the rock in the back seat. His hour of public service fulfilled, the police sergeant writes up a "rock solid" contract that allows Mallory to keep the rock as a permanent loan; it must be returned intact if he no longer wants the rock.The family, together with Grandpa Mike, plan the next several monthly outings before heading out to the Mississippi Palisades State Park on the east (Illinois) side of the river. They enjoy a firefly chase that evening. Rufus, their pet Labrador, crashes into each of the players like a bowling ball whenever he hears "I caught one" and one by one the twinkling insects get liberated. Other insects are in season, too, like cicadas. Now that they've shed their protective shells, lots of screeching cicadas gather in the trees and bushes. The twins learn that the cicada's shells make a satisfying CRUNCH when you stomp on them.New surprises await the family the next morning as they hike the Sentinel Trail. Checking out a bat cave isn't such a good idea if your dog is along. Humans may not hear the bats squealing, but dogs sure do. Rufus takes off in the opposite direction. Mallory is off to the rescue, except that Mallory himself needs rescuing as he tumbles into a sinkhole. The trail gets steeper and steeper. Suddenly, there it is. The great Mississippi River. "How wide is the river?" Melody wants to know, reluctant to leave the magnificent view. She and her brother get a lesson on estimating distances, based on comparing it with things you already know, such as car lengths and soccer fields.To escape the next day's mist, the family decides to drive across to the Iowa (west) side of the Mississippi River to view the Palisades from a different viewpoint. They stop at the Visitor Center, where a short talk on the river's history is about to begin. They learn about the river's length and width, the origin of the river's name, and count the number of states on a map that use the river as a natural boundary.Melody soon gets bored and asks permission to go outside to watch a steamboat go by. She waves from a small wooden pier when a staff member sees her through the window. When the talk ends, Melody is nowhere to be found. The empty pier has everyone worried. Mallory acts on those fears and jumps feet first into the water. "Nope, she's not down there," he reports as he resurfaces.Rufus senses something's wrong and leaps out of the car as soon as the door is opened. He runs down to the pier, sniffs the air and races to the bushes. Unlike her brother, Melody is dry. Lured into the bushes by the call of a goldfinch, she's dirty and bruised, her clothes torn by branches. The escapades have come to an end, but the discoveries haven't. Could her brother's warm hands help Melody's bruises mysteriously disappear? Find out in Book 5, "A Stone's Throw" if Melody also has a "magic touch." Age-appropriate topics in biology, chemistry, physics, earth science, and math weave their way among non-science areas such as graphic and language arts, history, and values in each BioFables book.