You are the pilot of a spaceship which is carrying a new and dangerous power supply. The ship was stranded near Saturn, making your shuttle the best rescue vehicle (you are on a nearby base). The power supply, (called the Mad Angel) is no longer functioning as planned, and a tremendous explosion is imminent. To make matters worse, Saturn’s gravity has attracted the stranded ship and pulled it through its outer rings - meaning, of course, that you must pass through them to rescue the ship. Hostile alien ships are included for more excitement.