Two Mexican American siblings travel with their parents on a business trip to Mexico, where they visit the impressive Maya ruins of Chichen Itza accompanied by their boss's grandkids and a quirky company chaperone. But their exploration of the tourist attraction goes sideways when the kids sneak into the Pyramid of the Feathered Serpent and fall into the secret cenote beneath. As they emerge from a vast underground lake, they realize they've been transported to another world, full of super-sized creatures... and even bigger kaiju!