|Air Date (US)||Aired online|
|Air Date (France)||November 10th, 2007|
|Written by|| Bruno Regeste|
|Storyboard by|| Nicolas Moschini|
|Preceeded by||Fight to the Finish|
|Followed by||X.A.N.A. 2.0|
The Lyoko Warriors have beaten X.A.N.A. and are about to turn off the Supercomputer but the four other members of the team - except for Yumi - don't want to turn it off for profound reasons of their own, and while they are at lunch Sissi puts a tracking device on Ulrich, determined to uncover their secret at last. During the episode, each member of the team has to confront their own reservations about shutting down the Supercomputer; Jeremie is afraid of losing his best friends, Aelita is afraid of closing the book on her past life, and Ulrich and Odd just miss being heroes and the action. However, all of them are forced to face the reality of the situation when Sissi announces to them and her father that she knows everything about them and their adventures on Lyoko (having used the GPS tracker to locate the factory), but her father, thinking she was nuts, starts dragging her to the parking lot.
With their worries consoled (including Ulrich's, who is reassured by Yumi that they can make new memories together), for the very last time, the group initiates a return to the past and wipes all of the memory of that day. This time around, Ulrich stops Sissi from planting the tracking device on the repeat attempt, telling her that they might be friends if she just stops messing with them, Ulrich and Yumi finally reforge their deep and close romantic relationship at last, and become boyfriend and girlfriend. The Lyoko Warriors go to the factory and finally shut down the Supercomputer and accept that fact that it is time to move on, closing the book on their adventures...for now.
Then it shows images of the warriors on Lyoko. Ulrich in the Mountain Sector who gave a slight nod to the camera. Aelita was in the Forest region and waved at the camera. Yumi was in Sector 5 who smiled. And Odd was in the Desert Sector who said "So long."
- The original French name for this episode is Souvenirs.
- Just before the ending credits begin, the supercomputer's cover flashes white, possibly hinting at X.A.N.A.'s miraculous survival.
- The Lyoko Warriors, including Jeremie all broke the fourth wall at the end of the episode by saying goodbye to the viewers. In order of appearance, Yumi's farewell clip comes from The Key, Ulrich's from Crash Course, Odd's from Deja Vu, Aelita's is created for this episode, and Jeremie's from Replika, Bragging Rights, or A Space Oddity (since it is a reused clip). X.A.N.A.'s 'farewell' is, like Aelita's, created for this episode only.
- William was the only member of the group not to join the others for the shutdown of the supercomputer, despite him being associated with Lyoko. He is also rejected by Yumi in the episode.
- One of the flashback clips of Odd was from the episode, A Fine Mess when Yumi was actually in Odd's body, but the voices were not the same because Moonscoop switched the audio to Odd's voice.
- This is the final episode in which 2D animation was used for the scenes of the real world.