In a futuristic USA, it’s forbidden to give birth to more than one child for each woman. As usual, you can escape to Mexico to avoid the authorities in USA, which is exactly what John and Karen Brennick were trying to do when Karen is pregnant with her second child (their first child was born dead). When they think they have made it they are discovered and put to prison (for 31 years), a modern prison called the “Fortress” where the prisoners are controlled by lasers, neutron-cannons, cameras, mind-scanners and electronic pain-causing devices in their stomachs. With those odds, John still plans to escape with his wife.