After the celebration Ayla and Ioka Village threw for Crono and his friends in 65,000,000 B.C., they awaken to find that the Gate Key was stolen from them. Ayla suspects the Reptites, so they plan to head south for the Reptite Lair, but not before making a quick stop in the Hunting Range where they encounter a Nu.
In order to reach the Reptite Lair, they must first pass through the Forest Maze. Near the entrance to the Maze, they find Kino. Kino admits stealing the Gate Key because he was jealous of Crono. He thought Ayla liked Crono more than him. After an apology, Kino says the Reptites took the Gate Key from him.
Sending Kino back to the village, Crono and his party travel through the Forest Maze and enter the Reptite Lair. They battle prehistoric creatures and eventually find Azala, who has the Gate Key. Azala then unleashes Nizbel on them. Eventually Nizbel is defeated and Azala becomes frightened of their strength. She unwillingly hands over the Gate Key. They travel back to Ioka Village where they recover their energy before making their way back to the Time Gate at the Mystic Mountains.