In Simon Bloom, the Gravity Keeper, Simon Bloom and his friends used the Book of Physics to narrowly defeat villainess Sirabetta. Now Simon's nemesis, stuck as a helpless thirteen-year-old, wants revenge. In this exciting sequel, Simon and company must enter the mysterious undersea realm of the Order of Biology to find Sirabetta before she can restore her powers. Aided by old allies and some new ones, the kids struggle with fierce beasts, dangerous enemies, and their own evolving abilities. Blending humor, suspense, and science – and throwing new octopus powers into the mix – Michael Reisman brings us another outstandingly original adventure.