Alcawell was a planet located somewhere in the space of the galaxy's Delta Quadrant, the homeworld of a native civilization that used time travel in much the same way as spacefaring civilizations used interstellar travel. Alcawell's history was divided into specific periods, each of which comprised 500,000 years of real time. Travel between different periods was an everyday activity among the natives of Alcawell; however, strict rules were enacted to govern the use of time travel: