In the town of Weaverton, signs of a circus are being posted. In Zeke MacGruder's barn, a group of boys are holding a meeting. Two brothers, Tommy (Chance Michael Corbitt) and Ben (Ryan Todd) are daring to climb Thunder Mountain, where it is said a giant lives. The boys take the dare and set out up the mountain. They get caught in a thunderstorm and barely escape getting hit by lightning (this is what gives Thunder Mountain its name). They take refuge inside a strange oversized log cabin. Whilst there, they find mysterious carved wooden figures. Suddenly, the giant returns and finds the boys hiding under a table, but they escape with one of the wooden figures and go back to town. When they reach home, they tell their family their amazing story, but no one believes them. The next morning, they set out with another boy, Zeke MacGruder (Daniel Pipoly) who doubts Tommy and Ben have seen the giant. Tommy and Ben's younger sister, Amy (Noley Thornton) follows them, but almost gets caught in a bear trap. The boys tell her to leave but she persists and continues following them.