Dr. Rick Marshall, a disgraced scientist, obsessively works on a time-warping device, hoping to prove his theories on parallel universes. His efforts land him an interview with Holly Cantrell, a research assistant who admires his work. She persuades him to test the device at a peculiar tourist attraction run by Will Stanton. When they activate the device, the trio is unexpectedly transported to an alternate dimension, a prehistoric world filled with dinosaurs, strange creatures, and surreal landscapes.

As they navigate this chaotic environment, they encounter Cha-Ka, a primate-like creature who becomes their guide and ally. The group struggles to find the warp portal to return home, confronting both fierce predators and an assortment of bizarre inhabitants. Through a series of adventurous and comedic trials, they must rely on their ingenuity and teamwork to survive and figure out how to reverse the portal, all while uncovering bizarre and previously unknown aspects of this mysterious land.