Set in the year 2912, the player takes the role of Kyle Brennan, an Earth test pilot for the X-Shuttle, better known as the X-Perimental Shuttle, which has the ability to jump from one part of the universe to another via a wormhole without requiring a jumpgate.
During the test jump, something goes drastically wrong and Brennan ends up in an unknown part of space. He encounters an alien race, the Teladi, a highly capitalist, profit-focused culture. Finding Kyle helpless, they repair his ship and loan him some money. They also give hints on trading in the X Universe, and may tell him (if he asks) about the Argon and other alien races in the X-Universe. The X Universe is a network of sectors linked by jumpgates. With his jumpdrive destroyed, and no idea how to return to Earth, Brennan finds himself stranded, alone and indebted to an alien race.
Source: Wikipedia, "X: Beyond the Frontier", available under the CC-BY-SA License.