It's 2274 and the world has been decimated by holocaust and left to it's own. The world most people know is the enclosed dome society. They are told not to try and go outside and they don't, for the most part. The world of the future is one in the pursuit of pleasure. You have very few responsibilities. So you go for all the pleasurable aspects of one's desires. There is a catch, you only live to 30. When you turn 30 your life clock that you have in your hand will turn color. So you go to carousel and your life is terminated.
Here's the problem some people don't want to be renewed as you are told you will be at carousel. They consider you dead at carousel so they run and get the name runner. Here is where the sandmen come in they go after you and catch you and terminate. Logan (Michael York) and Francis (Richard Jordan) are sandmen. They love the chase, capture, and then termination of the runner. It's a game to them, but hey it's a living.
Logan receives orders one day to infiltrate an organization of runners as they are proving to be a problem. The other night he had ordered a girl for the evening for some pleasure and Jessica-6 (Jenny Agutter) showed up. It was through her that Logan would meet Doc (Michael Anderson Jr.) and Holly (Farrah Fawcett) members of the underground organization of runners. Now Doc catches on to Logan but he is able to get away. So they are able to continue the mission.
Logan and Jessica do eventually make it to the outside of the dome. What they see is nothing they have ever seen before. They run into an Old Man (Peter Ustinov), something they have never seen.
What do you do now? Your outside, all that you have ever been told is a lie. So what do you do? Watch the rest of the movie and find out. Director Michael Anderson has put together one of the better futuristic movies ever made. This movie is one of those that if you think about it you know it could happen to us. So stop and take the time to see what might be if we live that long.