The story is divided into three major scenarios, each with a different main character: the soldier Sion, the priestess Riza, and the archaeologist Surlent. As the player enters new areas and accomplishes different tasks, the human race's final 15 days slowly ebb away in a predetermined day/night cycle. The player is free to play the scenarios in any order, and may even leave one storyline to follow that of another character for a time. The actions of the characters in one location and time may have an effect on the others, as well, both in the general story and in gameplay. For example, if one group of characters leaves a sacred relic somewhere, another character may come and find it on a later day in their own part of the game. After successfully completing all three scenarios, players must take on a fourth, featuring the roving thief Dune and the heroes from the previous three chapters in their final confrontation with the game's major villains.

The story is divided into three major scenarios, each with a different main character: the soldier Sion, the priestess Riza, and the archaeologist Surlent. As the player enters new areas and accomplishes different tasks, the human race's final 15 days slowly ebb away in a predetermined day/night cycle. The player is free to play the scenarios in any order, and may even leave one storyline to follow that of another character for a time. The actions of the characters in one location and time may have an effect on the others, as well, both in the general story and in gameplay. For example, if one group of characters leaves a sacred relic somewhere, another character may come and find it on a later day in their own part of the game. After successfully completing all three scenarios, players must take on a fourth, featuring the roving thief Dune and the heroes from the previous three chapters in their final confrontation with the game's major villains.