About the characters

- First time Ulrich rides on the Overboard.
- First time a character other than Ulrich uses his sabre.
- Ms Hertz gives detention to people who skip her class.
- Yumi would sometimes like to tell the truth about her friends’ secret to her parents.
- The principal calls Odd parents in his office, this is the first time they’re involved in any action…

About errors

- How can Yumi talk to Aelita without the microphone?
- The principal’s eyebrows are grey when he talks to Odd’s mother on the telephone.
- It says it’s Monday at the bottom of the screen at the start of the episode. If you want to be nitpicky, you’ll notice that it’s already Tuesday at 3 in the morning because our heroes only get 4 hours sleep.
- After Yumi cuts the Tarantula’s front legs, in the next shot they’re intact.
- Yumi’s outfit is reversed in one scene when she jumps over the Tarantula.
- The iron bars Sissi broke change colour when they roll towards Ulrich, Odd and Jeremy.
- Odd’s pants are entirely the lighter shade of purple when Yumi says that Ms Hertz has given them detention.
- Odd’s undershirt disappears from his torso when the four fighters exit the lift at the start of the episode, and when Sissi demands to know what the group is up to.
- Sissi’s belly is the same colour as her skirt when she’s stunned to hear Ulrich wants to ask her something.
- Sissi’s hair disappears when she spies on Jeremy and Aelita up until when she stops the recording.
- When the spectre leaves Sissi, in the following shot it’s not the same.
- Herb’s hair is entirely black when he’s amazed to see Jeremy on the ground and when Sissi takes an iron bar.
- When Sissi becomes herself again, the damage she caused to the wall is not visible anymore when there was no return trip.
- At the end Yumi says Ms Hertz gave them 4 hours detention each, but she’s not in the same year as the boys and Aelita and therefore Ms Hertz shouldn’t have punished her as well.
- During Ms Hertz’ class, Nicolas disappears and is replaced by Caroline Savorani who’s in year 9.
- The factory microphone disappears from Jeremy’s ear, reappears after the second RTTP, and before he sees XANA launch the RTTP it’s in his right ear as well as when he succeeds in stopping the RTTP.

About the series

- French title: Un grand jour

- First mention of pencak silat, Ulrich’s martial arts style.
- First time a tower is deactivated but no return to the past is launched.
- First episode in which Sissi is XANAfied.
- First episode beginning in Sector 5.
- Second episode in which the RTTP is launched more than one time.
- Falling from a great height costs life points on Lyoko.
- Ulrich: "No sweat, it’ll be just like the good old days!"
Allusion to season 1 in which they didn’t have vehicles.
- Mr Ishiyama seems angry at the idea that Yumi comes home late because she’s seeing a boy, even though he was happy with the answer in the previous episode.
- There’s no return to the past at the end of the episode, so we can ask why there was no suspicion about the destruction of the boiler room and Sissi's behaviour.
- Aelita hides by making a rock wall around herself with her Creativity, just like in episode 23, “Rock Bottom?”. The design of the rock and Aelita’s movements as the Hornets break it down are almost identical, right down to the camera angles.