Mrs Pepperpot has a problem - a huge problem - she shrinks! And when she shrinks she finds herself in all sorts of trouble. Mrs Pepperpot is determined to practise her swimming, so when all the village children go for a picnic in the mountains she goes to the pool in the wood. But disaster strikes - just as Mrs Pepperpot jumps into the water she shrinks! Now the pool seems as big as an ocean. Luckily there's a friendly frog nearby to rescue her and give her swimming lessons.