Matthew, Sooty and Soo are trying to get a new computer working, but can't manage. Matthew finds Sweep and Scampi playing with the wrapping that the computer came in and gives them into trouble. Matthew goes to the computer shop for help. When Matthew is out they get a customer looking for spare parts, he offers to help them with the computer and manages to get it working. While Sooty and Soo are doing that, Sweep and Scampi are busy trying to catch a mouse. In the end it is caught and Professor is gone by magic, Matthew returns home to find that the computer is working and that it was his fault because he never switched it on!
