About the characters

- Jeremy is interested in working in science later in life.
- Odd uses gel to spike up his hair.
- Ulrich’s flashbacks are extracts from episodes: Teddygozilla, Log Book, Big Bug, End of Take, Satellite, Swarming Attack, Laughing Fit and Claustrophobia.

About errors

- In this episode, one of Odd’s arrows appears to have homing capabilities (made to look like he angled the shot).
- At the moment when Jeremy leaves the infirmary, the door is green.
- The red halo of the activated tower disappears after Jeremy announces Yumi’s loss of life points.
- When Odd takes his skateboard, we see Yumi’s resting on the wall even though she picked it up in the shot beforehand.
- At the moment when the factory computer says “Ulrich and Odd vs Krabe” there’s only one red and one green icon instead of two of each. The back of Ulrich’s card also has Odd’s paw print symbol instead of his own circular symbol.
- When Yumi is devirtualised, the back of her card shows Ulrich’s circular symbol instead of her own, which is the same flower pattern as on her Lyoko outfit.
- The open hours of the infirmary disappear when Yolande tells Sissi that Ulrich is well and when she watches the two leave.
- The factory microphone disappears from Jeremy’s ear when he tells Yumi that Ulrich still has amnesia, and it changes often (wired or wireless).
- During Ms Hertz’ class, we see Pierre François, Tristan Brossard, Mohamed Kantaoui of year 7, and Sandra Dialo and Anne-Sophie Munier of year 6.
- Ulrich’s flashbacks with dialogue were re-voiced with new lines, meaning they’re inconsistent with what actually happened.
- In the Ice Sector, Ulrich said “ouch” when he fell onto the ground, but since they don’t have a sense of touch on Lyoko, he shouldn’t have felt pain…

About the series

- French title: Mémoire morte

- First time we see XANA virtualise its monsters.