Miss Graves is called to the doctors when it is believed that she has medical problems until it is revealed that it was just a mix-up, however rather than returning to school she decides to take the rest of the day off. Back at school, Mr Besser is forced to take over as the substitute teacher for the class and soon appoints Polly to take over his duties in order to get rid of her infuriating ways. When Vinnie writes an essay in which he calls Mr Besser a cold hearted liver butcher, he thinks that he is going to end up in permanent detention until he realises that he has misspelt Besser, saving himself from punishment.