At the start of the summer, Tia is excited to see all the visitors arriving for their holidays on Gull Haven Island, and she's delighted to make a new friend. But Tia's feelings change when some selfish tourists upset a newborn seal pup and its mother, and then she sees ho w people are carelessly leaving their rubbish on the beach. Can Tia find a way to show people how to respect the island environment and all the creatures that live there?