With time travel and mysteries that need solving, the Galactic Academy of Science (G.A.S.) series instructs readers on how to think like scientists. Under the guidance of a Dude or Dudette from the future, the middle school characters are faced with treacherous, present-day crimes that require a historical knowledge of science in order to be solved. From investigating problems to analyzing data and constructing explanations and solutions, this series blends elements of sci-fi with educational methods that distill the key thinking habits of scientists and engineers.Learn to create and crack codes in this latest G.A.S. installment Dr. G and his companions are using coded messages in a plot to corrupt the International Science Fair. Quarkum Phonon, a Dude from the future, calls on four middle school students for help. Benson and Anita work on their computers while two new G.A.S. recruits, Ella and Shomari, travel through time, facing kidnappers, thieves, and spies in their scramble to lea