Shawn and Gus are put on the case when a food critic is murdered. However, Gus' Uncle Burton is in town, and due to a misunderstanding, Gus must pretend to be the psychic detective to avoid disappointing his family.
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 room to fetch the backup programs, but forgets that it's Fire Safety Day and runs into several teachers, eventually having to scale the roof to get to his room. Meanwhile, the Skid stumbles upon another Lyoko and is attacked by two eel-like monsters. Jeremy is able to repair the navigation system and bring his friends home, after which he surmises that the replica of Lyoko is created from the portion of the Keys to Lyoko that X.A.N.A. has stolen from Aelita's subconscious in the second season finale, The Key. Jeremy wonders how he plans to use it.
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 Aelita and Jeremy stay up late to set the program up, they are caught and given detention. Meanwhile, William takes the opportunity to attack the incomplete ship, forcing Yumi to run the Supercomputer in Jeremy's absence. Odd and Ulrich are unable to handle the situation, but Jeremy and Aelita are able to sneak out in time to help. Aelita is able to repel William with a massive attack, allowing Jeremy to complete the sub on time. It is later christened the Skidbladnir, nicknamed "the Skid" by Odd, after the Norse ship.
What appears to be a Pokémon Center turns out to be a mysterious gate to a world where the gang's dreams all come true. However, they begin to realize that a Pokémon has them in a hypnotic trance.
After Don wins an award, his photo is featured in Advertising Age. Don must deal with the fallout as the photo brings back a past he isnt ready to confront. Ken gets a short story published in The Atlantic Monthly, inciting jealousy among his colleagues and driving Pete to make an unorthodox request of his wife. Peggy overhears a startling conversation in the office and shares the secret with Joan.
With Michael's assistance, Fiona helps a man who has been framed for the theft of an expensive brooch.
Jack and Victor discover Pete the Jakey was the inventor of The famous Beefy bake and seek recompense on his behalf. Tam and Frances are having marital problems. Who can offer counsel, Navid?
Chronicles of NFL teams' preparations for the season.
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 program malfunctions and bugs up the tower, allowing X.A.N.A. to take it over while Aelita cannot shut it down. As the William clone lashes out at the group, the real William is on Lyoko to keep the tower under X.A.N.A.'s control. Jeremy manages to repair the tower in time for Aelita to reset it, restoring the clone to working order. With a return trip to the past to erase the unwanted memories of William's behavior at school, the group elects Sissi as the rec room monitor.
Can you sneeze with your eyes open? And if you do will your eyeballs pop out of their sockets? Can you stop a speeding car by putting it into reverse? Could a tennis ball with a hole cut in it pick a lock?
The Gavin clan stages an intervention after several disturbing family calls; the mysterious woman (Gina Gershon) from the restaurant leaves Tommy wanting more; Janet must take matters into her own hands to get her baby back; and a depressed Mike calls Tommy in a moment of despair
This episode details outer lying planets and their moons. Included will be Uranus, Neptune, and Pluto. Using CGI, we will also see what alien life might look like on other worlds.
Mike Rowe gets dirty as he braves the untamed world of Vomit Island, a place where few have ever been and even fewer would ever want to go. Mike's mission is to help band and count newly hatched herons on the poo covered island.
One of the Global Dynamics tanker trucks spills, potentially causing a change in everyone's sleep habits... In the course of the episode, we come to learn that Global Dynamics has developed a technology that enables them to distill six months of the town waste and by-products into one truck, an amount that would normally fill Lake Erie.
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 time to do this, he activates a tower and uses it to create a a clone of his own to attend class in his place. Meanwhile, William's absence is drawing attention, from both the principal and his father. While Jeremie's Clone is impressing Jim outside, William appears on Lyoko and tries to put the tower under XANA's control. In order to maintain his clone, Jeremie draws energy from Sector Five to maintain the activated tower. He eventually runs out of energy and the tower is put under XANA's control. While Odd holds the Jeremie Clone off, Aelita, Yumi, and Ulrich go to Lyoko with new outfits and powers. They eventually deactivate the tower and stop William, who tries to push Yumi into the digital sea. She is saved by Odd at the last second. Jeremie then does a return to the past and replaces the Jeremie Clone with a William Clone to prevent any suspicion about his absence.
Katie is getting ready for her upcoming deposition in the Frobisher case while Gregory withholds information that could be even more important that Katie's.
After being threatened by U-Turn and The Armenians, Nancy goes in search of Silas and her hijacked pot. Meanwhile, Celia has Silas arrested for stealing her "Drug Free Zone" signs. Nancy visits him in jail only to discover that the pot is still in his car - the one that Celia has just driven away in.