A great new technology has been invented by scientists. Through this technology, humans can be reduced to only 5 feet tall, which means that humans will consume less resources and have more space for activities. Paul (Matt Damon) and Audrey (Kristen Wiig) are a couple trapped in poverty. In order to enjoy a better life, they decided to undergo a shrinking experiment. But just before the experiment was about to take place, Audrey regretted it, and only Paul shrunk successfully. At the beginning, everything was so novel for Paul, who had become smaller. He lived in a community specially built for shrinking people and had an unprecedented new experience. But as time went on, problems emerged one by one. The society of small people was not much better than that of adults. What's worse, Paul and his wife had a rift in their relationship because of the huge difference in their body shapes.