Mind Your Language season 1 episode 13: The students prepare to take their Lower Cambridge Certificate exam at the end of the first term. Meanwhile, Mr Brown has a disagreement with a couple in the pub, which comes back to haunt him when it turns out that the man (Mr Short, a former principal of the school) will be supervising the exam.

Ali, Giovanni and Max are at The Red Lion. Ali is playing the slot machine, but loses all his money and can’t get any change from Giovanni or Max. Ali asks Mr. Brown for change when he arrives, but Ranjeet comes to play the slot machine and wins the jackpot. Ali and Ranjeet start arguing over the money, but Mr. Brown settles their dispute by suggesting that they share it.

After Mr. Brown tells the students to go back to class, a lady mistakes him for a waiter when she sees him carrying Giovanni and Max’s glasses. She orders a gin and tonic for herself and a lager for her husband and refuses to listen when Mr. Brown tries to explain that he isn’t a waiter. Mr. Brown acquiesces and buys the couple’s drinks, but the man notices when Mr. Brown accidentally takes a sip of his lager. He refuses to pay for it when Mr. Brown brings it to his table, and his rude and arrogant behavior causes Mr. Brown to pour the lager on his head.

At the school, Miss Courtney asks Mr. Brown’s students where he is. Giovanni and Max try to make up a story, telling her Mr. Brown went to the tearoom and then to the toilet, but Miss Courtney doesn’t believe them. Mr. Brown finally arrives and tries to tell Miss Courtney the truth about why he was late, but she says that he is a “bigger liar than [his] students.”

Mr. Brown gives the students an overview of the Lower Cambridge exam, which Miss Courtney tells him that Mr. Short, the school’s former principal, will administer to his class. The male students make plans to cheat on the exam but are found out by Mr. Brown when he sees ink smudges on Giovanni‘s hand. Mr. Short, the man from The Red Lion, arrives and sends Mr. Brown away so he can administer the exam. Mr. Brown goes back to the pub to wait, where he talks to Mavis about his students and his cat.

Mr. Short dismisses the class after the exam and has some sherry in Miss Courtney‘s office. He tells her about the students’ poor performance on the exam while Mr. Brown and the students celebrate the end of the term with drinks at The Red Lion. When Mr. Short returns to the pub to meet his wife, Mr. Brown accidentally sprays him with a soda syphon, and Mr. Short gets back at him by grabbing a drink off of Mavis’s tray and pouring it on his head.