Amaranth III directly continues the story of the second game. The knight Lyann Fremdes and his lovely companion, the elf Din, the heroes of the game, head to the city of Dematria, where Din is met with joy; there is even an article about her magical healing powers in a local newspaper. All goes well till the heroes decide to visit the city Magnelia. A hostile army invades the train station and massacres people. Looks like Lyann and Din have to hide for the time being, before they can think of a secure way to stop the enemies - which is anything but easy, since the enemy seems to possess advanced technology...
Amaranth III differs from its predecessors in several ways. It has a more modern setting, with steam-punk elements. The gameplay system has been re-vamped, becoming closer to a strategy RPG than to an action RPG. As before, the battles feature free movement, but it is turn-based now, with action points for each characters; the character can act as long as he/she still have action points left. There is a "Vigour" system that keeps track of characters' stamina; once the vigour is lowered, the character begins to lose hit points. Using special items and resting in inns restores vigour.