In a distant galaxy is a star system containing eight planets in which profits could be made trading between each planet until space pirates came along and robbed the traders on their trade routes. The traders could fight and die or get taxed by the pirates for a 1/4 of the value of the cargo and now all the traders have given up or left the star system. You are the only trader left and you now have the opportunity to trade between all eight planets being careful to avoid any pirates on the way.
An early example of the space trading genre. The game involves a single player moving from star to star on a map of the galaxy, buying and selling quantities of six types of merchandise in order to make money.