Jack McKee is a doctor with it all: he's successful, he's rich, and he has no problems.... until he is diagnosed with throat cancer. Now that he has seen medicine, hospitals, and doctors from a patient's perspective, he realises that there is more to being a doctor than surgery and prescriptions.

People in the future live in a totalitarian society. A technician named THX 1138 lives a mundane life between work and taking a controlled consumption of drugs that the government uses to make puppets out of people. As THX is without drugs for the first time he has feelings for a woman and they start a secret relationship.