Half a year.
It's been half a year since the supercomputer was turned off.
Odd and Ulrich broke the habit first (well, technically William was first), but they still remember. Yumi broke it a little afterwards, despite having wanted to turn off the supercomputer first. Jeremie was hard to lose the habit. He would carry the laptop everywhere, still occasionally nervously glancing at it, expecting it to suddenly beep. He jumped out of his chair a few times, reacting to other beeps such as cell phones, etc. Aelita broke the habit last. She would visit the Hermitage constantly, in her free time. Reminiscing on echoes, taking souvenirs, such as the book on norse mythology. She would go to the Factory too, they all would visit every so often, but none of them ever went further into it than the main atrium.
Life was peaceful. They still had classes together, except for Yumi and William, obviously. Jeremie and Aelita maintained a constant high, possibly even higher, grade. Odd, Ulrich, Yumi, and William each had their grade pick up a bit compared to when they were being heroes. Outside of Lyoko, their only worries were school. Aelita occasionally pondered her mother, her past, her forged existence. Aelita Stones. Not Aelita Hopper. Not Aelita Schaeffer. She sometimes worried when things like the future came up - driver's licenses, college applications, resumé. Jeremie assured her that everything would be fine. He covered all his tracks and all future tracks.
"Quiet down, children. We have special guests here today, from America, for the Psychology course." The students settled down from their idle chatter and focused on the entryway to the classroom. Principal Delmas and the psychology teacher both lead in a middle-aged man, dressed semi-formally, followed by a middle-aged lady dress more formally, a younger man dressed rather informally, and a younger woman dressed semi formally.
"This, is The Lightman Group," Mr. Delmas stated clearly.