The film is set against the backdrop of the mythology of the Classic of Mountains and Seas . It tells the story of Peng Lai, a junior high school girl, who accidentally enters a mysterious cave that seals ancient books during her summer vacation trip and releases four ferocious beasts: Qiongqi , Hundun (Dijiang), Taotie , and Taowu . In order to restore world order, she uses the power of the mountain and sea beasts she has subdued to fight against the ferocious beasts. In the end, she successfully repairs the book and achieves self-growth.
Let's Pretend was a 1980s children's television series aimed at preschool ages. It was shown across the ITV Network at 12.10 on Tuesdays, then later Mondays, replacing the popular Pipkins which had been cancelled at the end of 1981. Like its predecessor, each edition was fifteen minutes long, and the programme was produced using many of Pipkins' personnel such as puppeteer Nigel Plaskitt and producer Michael Jeans.
Each week the presenters would find a number of ordinary household items and contrive to produce a short story featuring them all. The first programme, "The Story Of The Broken Puppet", was shown on Tuesday 5 January 1982 by Central Television. The show aired weekly until 1988.
The show's original opening titles featured items moving along a conveyor belt into the mouth of a large plastic whale, and later a puppet caterpillar moving along the screen.