Back To The Future Part 4 is the story about Marty, Doc Brown and Fe Fei. In last scene of Back to the Future Part 3, Marty asks Doc if he's going back to the future, but Doc tells him that he's already been there. Doc Brown and his family go to the Wuzhen, Chine where Fei Fei lives. Marty invented again the second DeLorean time machine just like in Back to the Future Trilogy. Marty went to the Wuzhen to see who is Fei Fei and why she still believe to Chang'e is exist. When Marty and Doc go to meet Fei Fei and she tell about the story about how she went to the dark side of the Moon just like the story in Over the Moon. Marty and Doc decide go to the moon using DeLorean time machine. The time machine become teleport machine (mixing time and teleport machine). Fei Fei invented again her rocketship to push delorean up to 600 km/h to reach 100 km. If they reach 100 km to accelerate 600 km/h, the Delorean and Rocketship teleport travel to the dark side of the moon and reach to Lunaria where Chang'e live. Fei Fei tell Marty and Doc wants to show Chang'e is alive.
