Hanna and Leon are spending their vacation with their Aunt Birgit on an island. The children can hardly wait to finally see their favorite animals: dolphins. Together with their aunt, they take a trip on a boat belonging to a friendly captain. During the outing, the children even discover a baby dolphin playing joyfully. But suddenly, the little dolphin disappears! Captain Isidoro dives after the animal, which has become entangled in a fishing net. He manages to free it and brings it onto the boat. The children are allowed to help keep the little dolphin wet. Together with Aunt Birgit and the captain, they take it to an animal rescue station, where a veterinarian takes care of the dolphin. Since the baby dolphin is only lightly injured, the rescuers release it back into the care of its mother in the open sea. A few days later, the little dolphin and his...