Felix's favorite toy, a robot dog, is lost in the land of the trolls. With a little help from an all-seeing troll witch, Felix and Calcite get close to finding it. That's when they learn a big problem is standing in their way: Garganto, a giant who guards the path ahead. Garganto says no one gets through his gorge—even if Felix's toy is on the other side. But he's never met a duo like Felix and Calcite!