Izzy Steam, an eleven-year-old aspiring biologist with a case of anxious perfectionism, arrives at Science Valley Boarding School and feels right at home. Alongside her ambitious new friends Dani and Micah, it's as if the school were made for future scientists like her. But soon, worry starts creeping in: Am I really smart enough to be here? One night, Izzy happens upon a curious bone in Micah's collection of treasures from the Science Valley woods. The bone sends her into a molecular mystery, requiring every ounce of her brainpower to solve, not to mention the cutting-edge tools from the Science Valley research labs. With the help of one of her teachers, Dr. Pabo, Izzy learns that the bone contains not-quite-human DNA. It's certainly not an animal, either. One thing's for sure: The bone is very old. So old, in fact, it could be a link to humanity's ancestral past. As she solves this ancient mystery, Izzy might make even greater discoveries than she bargained for. With the help of her team, Izzy learns that the best results aren't perfect, mistakes are expected, and wrong turns are part of the journey of discovery. Alternating between narration and excerpts from Izzy's lab notebook, Molecules and Mystery Bones is a tale of a worried girl's deep exploration into life, science, and her place in this mysterious world.