Complex sentence: Parts I, II, and III were released in reverse order, while Part IV was released just over eighteen years after Part I. The songs do not follow a set storyline; instead, they deal with topics relating to the emotion of "fear".
Split into simpler sentences: Parts I, II, and III were released in reverse order, while Part IV was released just over eighteen years after Part I. The songs do not follow a set storyline. Instead, they deal with topics relating to the emotion of "fear".