It tells the story of the gunslinger, Roland of Gilead, and his quest to catch the man in black, the first of many steps towards his ultimate destination - the Dark Tower. The main story takes place in a world that is somewhat similar to the Old West but exists in an alternate time frame or parallel universe to ours. Roland exists in a place where "the world has moved on." This world has a few things in common with our own, however, including memories of the song "Hey Jude" and the child's rhyme that begins "Beans, Beans, the Musical Fruit". Vestiges of forgotten or skewed versions of real-world technology also appear, such as a reference to a gas pump that is worshipped as a god named "Amoco", and an abandoned way station with a water pump which is powered by an "atomic slug".