After a series of events, Apes have gained intelligence and became the dominant species of Earth while most humans lost their ability to speak and some humans even reverted back to the caveman lifestyle.

Mae is a human female who is one of the few remaining humans with intelligence, and she's on a mission to restore intelligence and knowledge to humanity so they can live on Earth, despite the fact Apes are clearly in charge. One day, Mae is exploring an abandoned fortress full of the technology used by humans before they lost dominance, and she finds something interesting