What happens when the most unpopular boy in class discovers a mouse with a big brain and an attitude to match? Eric is about to find out. When Einstein escapes from the mad scientist Dr von Burpinburger, he is rescued from a pet shop by Eric – a boy with absent parents, few friends, and a lousy record at school. Thanks to telepathic prompting from Einstein, Eric suddenly begins to dazzle – winning academic and popularity contests at school. But the evil Dr von Burpinburger is on his trail. He wants his star mouse back! And Einstein is starting to get just a little out of control...