In Steam Power, two young islanders, Olive and Troy, enlist the help of a visiting inventor to build a machine that will make the rides at the amusement park much more exciting. After observing the power of expanding steam in a whistling tea kettle, they decide to build a steam engine! A steam engine is a device that converts heat energy to mechanical energy. The Islanders soon discover that using steam power can make the Mammoth Island far more thrilling -- from spinning cotton candy to powering roller coasters.