'Mum!¿ yelled Matilda as she raced into the kitchen. 'I saw you right through the brick wall of the garage!' Not everyone can see through a brick wall, but Matilda Mudpuddle suddenly finds that she can see through anything. This special power will only last for one month, but during this time she discovers a new source of water for the city, she identifies a gang of thieves and she and her friend Stephen even find a lost little girl. Most importantly she uses her X-ray eyes to help other people.