Thomas is a 10 years old child very cute and smart. His parents are at work most of the time and he spends a lot of time with his grandmother, a very funny 75 years old lady, that loves flowers and turtles. Grandma helps Thomas with his homework, particularly maths, a subject that gives Thomas some serious problem. In the garden there is a hidden hut full of stuff and gardening tools. Searching in the hut Thomas discovers a special game, a math labyrinth invented by his deceased grandfather. Grandma is a bit disappointed, but at the end she agrees to play with Thomas in the labyrinth where the two discover pirates, odd and even numbers, pearls, coloured rafts and geometric shaped cities. Going through many dangers they end up solving many problems and completing the game.
Thomas then becomes an expert that can teach the math game to other children.
The materials animated in the film come from the Montessori teaching methods of the “psico-maths”.