Bells and Mitch, space aliens from the planet Exergy, come back to Earth for more exciting adventures in science Our heroes dive deep into Earth's Pacific Ocean to solve a problem: how can they protect their home city on Exergy? Could the creatures living in the Pacific Ocean--who use camouflage to hide from predators--hold the answer? Join Bells and Mitch as they use the principles of the engineering design process to ask, imagine, plan, create, and improve their ingenious solution in Book Two of the Engineering Everything series.