Tikos loves his great-great-grandmother, Mrs. Siganí, very much. When he goes to her house, he has a wonderful time. She has delicious surprises waiting for him on the table and much more. With her, he learns a lot of new things about the sun, the rain, rivers, the sea, and people.

On the way to his grandmother's house, he saw a young lady. It was the first time he saw her, and he really wanted to meet her, to hang out and play puzzles together. Her name was Melonítsa, and she was also pleased to meet him. He took her to see his grandmother, Siganí, and she liked her at first glance.

However, his grandmother was very thoughtful that day because she discovered that the factory next to the river was dumping waste and polluting the river's waters. She discussed it with them and with Mrs. Savrína, who happened to be passing by. They decided, therefore, to teach the factory owner a good lesson, as he was only interested in money and didn't care at all about the harm he was causing to the plants, animals, and people.