Poor Geronimo! A training session on T-Rex approach techniques is already a challenge. But when his group is tasked, at the same time, with bringing water from the Puant marsh to Genny Geiger so that she can prepare the precious elixir that puts the dinosaurs to sleep, the day turns into a nightmare! The DINO agents accidentally fall to the bottom of a ravine, discover the dried-up Stink Marsh, ride impetuous probactrosaurus and... find themselves struggling with a spinosaurus, the only dinosaur larger than the T-Rex! The situation seems hopeless when providential saviors appear! Which ones? GÔedÔeon, Ornella and Prince T, the T-Rex family that the DINO agents brought together in In the footsteps of the T-Rex!