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. Mae and Clinton are fighting about whether a new vaccine is safe. But when protests against the vaccine threaten to turn violent, Selectra Volt insists that the two middle schoolers go on a mission together to find the truth. Mae and Clinton travel through time from ancient India to Europe, Australia, and North America. They witness the fight against smallpox, rabies, polio, and other viral illnesses as they visit Louis Pasteur, Jonas Salk, Macfarlane Burnet, Maurice Hilleman, and Andrew Wakefield. Will they return in time to uncover a vicious plot involving the new vaccine?

Pendred Noyce is a physician, an educator, and the author of The Baffling Case of the Battered Brain and The Desperate Case of the Diamond Chip. She is also the author of the award-winning middle-grade Lexicon Adventure Series. She lives in Boston, Massachusetts. Roberta Baxter is the author of several books, including The Bill of Rights, The Dropping of the Atomic Bombs, The Magna Carta, and Moving with Children: A Guide to a Smooth Family Relocation. She lives in Colorado Springs, Colorado.