Yesod is a world made up of four kingdoms, each taking its name and character from one of the four primordial elements: Air, Water, Earth and Fire. The four kingdoms are on the verge of civil war, due to the disappearance of the ancient Power, the magic that held them together, stolen by an Enemy who has already been beaten once but never completely defeated. Four young chosen ones, one from each kingdom, must go in search of the Keys of Power, the legendary talismans that will allow them to open the gates of the fortress of Atai, where the Power was guarded, which now lies closed and empty. Avir, Mayim, Karka and Esh, through adventures and dangers, undergo a process of discovery, learning to know themselves and to understand that victory and deliverance can only come from combining their strengths and differences.