Samantha Hansen is a mad scientist. Not the crazy kind - she doesn't blow stuff up, she just loves science (especially rocks) and figuring out how the world around her works. That is, when she can. For one thing, her bossy big sister can't seem to keep her hands off Sam's rock collection. And another, she just can't seem to control her 8-year-old temper. And there are some bigger questions that constantly elude her: How did her father die? And why won't her mom talk about him anymore? When Sam's mom announces an upcoming family trip to the Grand Canyon it's a dream come true. But it's also a challenge: if Sam can't learn how to count to ten and ignore her irritating sister she's going to miss her chance to see one of the world's biggest rocks and to find out the answers to some of her questions.