Tim ventures into the desert to test the safety of various gases for use in a blimp. Which ones will survive a spark, or will they all be blown sky high? It's disorienting science next when Tim makes a splash with a spinning disc and a set of colored dots. He also sets a healthy eating challenge that requires some out-of-the-jar thinking. Plus, a flame-boyant piece of equipment helps us to see sound, and an illuminating use for liquid nitrogen takes us to a Hollywood-style finale.