Code Lyoko: Season 4
Season 4 Lore Primer
Key plot threads, lore context, and character stakes you need to remember before diving into this season.
- Directly follows the overarching narrative developments of Code Lyoko Season 3.
- Faction dynamics and core character alliances shift under escalating external stakes.
- Crucial mysteries introduced previously reach key turning points and narrative reckonings.
- Sets up serialized story arcs that build directly toward the climactic season finale.
Episode Guide
Season 4 Progress Shield
William Returns
Aug 13, 2007
Using the data that Franz Hopper gave them, Jeremie and Aelita succeed in recreating Lyoko, which now holds only Sector Five. Soon after, William is devirtualized, and seems perfec
Double Take
Aug 14, 2007
In order to compensate for all of William, while under XANA's control, Jeremie sets to work designing new equipment for his friends and recreating Lyoko. In order to buy himself ti
Opening Act
Aug 30, 2007
Jim's nephew, Chris, the drummer of the Subdigitals, pays a visit to Kadic to look for an opening act for the band's next concert. Everybody tries out, and Aelita turns out to be t
Wreck Room
Aug 15, 2007
There is a new recreation room at Kadic and William's clone is put in charge of it. Meanwhile, Jeremy has developed a program to get the real William out of Lyoko. However, the pro
Skidbladnir
Aug 16, 2007
The new virtual, submersible "submarine" (as Jeremy calls it) is almost complete, the last step being a secondary program that needs to be run by 4 PM the next day. However, when A
Maiden Voyage
Aug 17, 2007
The gang manages to convince Jeremy to let them test out the Skid. During this test, the navigation system bugs up, leaving the gang stranded in the digital sea. Jeremy runs to his
Crash Course
Aug 20, 2007
Jeremy decides to teach Odd, Ulrich, and Yumi how to use the Supercomputer in case he or Aelita are unable to, being X.A.N.A.'s favorite targets. During the lesson, Jeremy is attac
Replika
Aug 21, 2007
The group travels to one of X.A.N.A.'s replica sectors in the Digital Sea. Meanwhile, Aelita and Odd get into a fight after Odd's desire to sleep in gets them both in trouble. Furt
I'd Rather Not Talk About It
Aug 22, 2007
The group turns to Jim for training, so they can be better prepared to fight against X.A.N.A.. However, things go bad when X.A.N.A. possesses a boar to attack them with, forcing th
Hot Shower
Aug 23, 2007
When a comet passes near Earth, X.A.N.A. uses a laser-equipped military satellite to split it into chunks, simultaneously aiming the bulk of it directly at the factory. Aelita, Odd
The Lake
Aug 24, 2007
Jeremy, Aelita, Ulrich, and Odd go with the rest of their science class on a field trip to an island in the middle of a nearby lake to study water-based plant life. Yumi, not part
Lost at Sea
Aug 27, 2007
Hiroki steals Yumi's diary and Ulrich finds it. Meanwhile, in a new attempt to free William from X.A.N.A.'s evil clutches, Jeremy creates a program to find William in the Digital S
Lab Rat
Aug 28, 2007
Jeremie has perfected his "Teleportation" process, allowing him to send his friends to the location of Xana's supercomputer in the real world to destroy it. He uses it on Aelita an
Bragging Rights
Aug 29, 2007
Having failed to destroy X.A.N.A.'s supercomputer in the Amazon, the group sets out to finish the job. Meanwhile, Odd's bragging gets the better of him, and he makes a bet with Ulr
Dog Day Afternoon
Aug 29, 2007
Odd tries to take Kiwi to Lyoko, but ends up absorbing him instead. As a result, Odd slowly begins to take on dog traits, such as enhanced smell and scratching himself with his foo
A Lack of Goodwill
Aug 30, 2007
Jeremy has developed a program to make the William clone smarter, but the learning curve is still problematic, as it tries to fling a glass into the air from a fork. Milly and Tami
Distant Memory
Aug 31, 2007
It's holiday time at Kadic and everyone is headed home. Aelita, however, has no home to go to. As she watches over Lyoko, she gets a message from Franz Hopper, who has constructed
Hard Luck
Sep 8, 2007
When Odd breaks a mirror, a little bad luck follows and jinxes him everywhere, even on Lyoko. A bug in his virtual avatar spreads to Yumi and Aelita, causing annoying pauses and ra
Guided Missile
Sep 15, 2007
Jeremy wins a contest to take a flight in an armed fighter jet, even though it is Odd who entered him into the contest. However, just before takeoff, X.A.N.A. possesses the jet and
Kadic Bombshell
Sep 22, 2007
When Sissi's pen pal from Iceland, Brynja Heringsdötir, arrives at the school, all the boys swoon over her, making Sissi envious. When Brynja takes an interest in Odd, he ends up s
Canine Conundrum
Sep 29, 2007
When Kiwi's mindless destruction becomes too much for the group to bear, they force Odd to keep him at the factory. As Odd drops him off, XANA possesses Jeremie's Kiwi Two robot, t
A Space Oddity
Oct 6, 2007
Because of a surprise dorm inspection, Odd has to convince Yumi to keep Kiwi at her house. Jeremie, meanwhile, has located the next Replika, a copy of Sector Five. Its supercompute
Cousins Once Removed
Oct 13, 2007
Jeremie's cousin, Patrick, comes to visit. Jeremie isn't entirely happy about it, since Patrick is "super cool" compared to him. Discovering another Replika, Jeremie and his friend
Music to Soothe The Savage Beast
Oct 20, 2007
Aelita's first concert with the Subdigitals is coming up, but Aelita's stage fright threatens to get the better of her. Odd meanwhile, has to find an extra ticket so he can bring a
Wrong Exposure
Oct 27, 2007
Aelita finds a photo of herself with Franz Hopper at the Hermitage, with a mathematical equation in the background. Jeremie discovers that the program works as a reset feature to L
Bad Connection
Nov 3, 2007
Odd is presenting one of his films, but is unhappy because his parents are coming. According to him, they never find fault in anything he does, which he finds dissatisfying because
Cold Sweat
Nov 3, 2007
When an embarrassing picture of Yumi is printed in the Kadic newspaper, she turns to Odd as the source. He manages to get Ulrich to take the blame, however, causing tension between
Down to Earth
Nov 3, 2007
In order to defeat XANA, whom they have vastly underestimated, Jeremie plans to design another multi-agent system to combat him. That, however, is still under development. In more
Fight to the Finish
Nov 10, 2007
With the Skid gone and XANA's Replikas at unmanageable numbers, Jeremie continues work on his multi-agent system. Meanwhile, Aelita has nightmares about her father being killed by
Echoes
Nov 10, 2007
With their mission completed, the group looks back on all their fond memories of Lyoko. Sissi, meanwhile, plants a tracking device on Ulrich in order to discover their secret. When