Crono's party heads to Fiona's Villa in 600 A.D. Fiona tells them that they want to start planting the seedlings to build their forest but can't due to the monsters underground destroying the dirt. So the party goes to the nearby Sunken Desert and defeats the creatures there.
After returning to Fiona, Robo agrees to stay behind and help with the process of sowing the seeds.
The entire 7 members of the party get together and spend the night in the forest. Lucca unexpectedly finds a Time Gate and travels back 10 years to the time her mother Lara lost her legs. She has a second chance to save her...
After the quick visit, she jumps back to the forest to rejoin the party.
- Note: It's up to the player to save Lucca's mother. Whether they are successful or not is one of the many events that helps determine the ending in the game after Lavos is defeated.