When Henry decides to get more pocket money, he starts to have a sale. Then his brain had an idea: Sell Peter himself!
The episode starts with Henry playing with his toy castle. Then he gets mad because the castle was rubbish and needed a proper one. He finds out that his piggy bank is empty and screams that he needs more money. Later, he complains to Mum about it, only to reply that 50p a week is enough. Peter then says that he saves money, making Henry angry and transforms into a Horrid Crab. Henry is then said that he doesn't get any pocket money for the following week, thus forced to "earn" money to save it up. He then puts ear wax on Peter's ear.
Later, he tries to set up a sale by selling some of his broken toys, including Dad's tennis racket and Mum's perfume. Ralph, Bert, and Al stop by at Henry's sale, already making 37p. Peter then saw his sale and complained that he was selling the perfume and the tennis racket. Henry then threatens him to sell him if he doesn't be quiet, then it gave him an "Eureka" moment: all he could do is sell Peter as a servant so Henry could get money and will get Peter back some money. Ralph then buys Peter.
At home, Mum asks Henry where her perfume went, he lies and said he hasn't seen it. Then she asks him where Peter went. He tells the truth and Mum gets angry at him. So Henry goes to Ralph's house to buy Peter back but when he got there, Ralph told him he sold Peter to Margaret and got £2 for him and Henry believed he was robbed.
Henry watched Peter serving for Margaret and Susan making him their slave. Peter begs Henry to rescue him by telling him that he'll give him all of his money. The two brothers made a new deal and Henry told Margaret that he has to be buy his brother back but she refused so he gives her £1,50. Margaret got Peter trained for £10 so Henry offered to take his place. The two enemies made a deal and Peter was free to go.
Henry brings the girls their drinks but Susan had to go so while Margaret sees her friend out, Henry makes a plan and then she comes back and he fans her when her chair was unbent. She gets trapped in an umbrella then she steps on her paddling pool and slips.
Margaret gives Henry his money back and tells him to leave. Henry was happy because now he's rich. In the car, Dad was amazed that Henry has a lot of money since he earned it just like he said earlier. Henry tells Dad the stuff he wants but he asked him if he'll have enough leftover.
Henry realised that he and Dad were going to sports shop where they sell tennis rackets and then the perfume shop where they sell perfume. Dad thinks Henry should have just about enough money and He screams "NO!" as they drive on.
- Horrid Henry
- Perfect Peter
- Rude Ralph
- Beefy Bert
- Aerobic Al
- Moody Margaret
- Sour Susan
- Gorgeous Gurinder (cameo)
- Horrid Crab
- This is one of the only six episodes where Horrid Henry and Moody Margaret both lose throughout the episode, the others are (Horrid Henry's School Fair, Horrid Henry and the Secret Club, Horrid Henry's Aquarium, Horrid Henry Gets A Job and Perfect Peter Popstar.
- This is the first episode where Beefy Bert says something else rather than "I dunno." (He says "Have you got any food?")