About the characters

- First time Odd is hit in the tail.
- First time Yumi uses her telekinesis to move a flying platform.
- Fourth use of Odd’s joke “Say something!” “Something…” by Ulrich this time.
- The girls are on the second floor and the boys on the first in Kadic’s dorms.
- Sissi is superstitious.

About errors

- At the moment when Ulrich gets out of bed, his clothes change.
- The handle of Aelita’s door is on the right instead of the left in one shot.
- The factory microphone wire disappears when Odd tells Aelita he found the activated tower.
- When Odd takes the headset to talk to Aelita, it’s not his arm we see but Jeremy’s.
- The marks under Sissi’s left eye disappear at the moment when XANA’s spectre disappears.
- The letter A on Aelita’s pyjamas disappears when she arrives at the factory with Jeremy, Ulrich and Odd.
- Herb’s hair is entirely black when he chants with Nicolas and after the RTTP.
- During the RTTP Kadic’s lights are on when that shouldn’t be the case in the middle of the night.
- The doors to the rooms in the dorms often change colour (brown, blue), Jeremy’s is blue when Ulrich enters and it becomes brown at the moment when Jeremy says there’s no activated tower.
- After Ulrich is electric shocked by XANA’s spectre, Jeremy says “We have to get back to the factory,” but they’re already at the factory; he should’ve said “We have to get back to the lab.”
- Jeremy wears his regular clothes when he gives instructions to his friends before going to Lyoko when he should be in his pyjamas, when he says “Virtualisation,” before launching the RTTP and during it.
- When Odd puts out the fire on his tail tip, we see that it’s scorched dark brown. In the following scene it’s back to its normal white colour.
- When Aelita tells Odd where to type the code Scipio, she tells him to type it in the third window on the second screen. However, the window is actually the second window on the third screen.

About the series

- French title: Esprit frappeur

- Kadic Academy was constructed in 1905.
- Final use of Odd’s joke “Say something!” “Something…”
- First time the Overboard enters a Way Tower on screen.
- First time a Tarantula destroys one of its own kind by accident.
- First time the heroes fail to activate the key (note that in “Unchartered Territory” they don’t even attempt to reach it). Yumi is the first devirtualised by the passage closing.
- First episode in which we see the Transporter outside of the Arena to take a hero out of the Sector.
- Fire and smoke are seen on Lyoko for the first time, on Odd’s tail to be exact, proving that fire exists to some extent in the virtual world.

About references

- The pentagram is a symbol with a star pointing towards the top of a circle, representing the five extremities of the human body.
If the star is oriented towards the bottom, it becomes the symbol of the Antichrist!

- Sissi: “We will bring together our Ping and Pong energy!”
Reference to Yin and Yang which, in Chinese philosophy, represent the opposing forces of the world.