Above Mainframe hangs the web creature's parting gift: A gigantic portal to the Web - a chaotic abyss filled with unspeakable horrors. It will take the combined might of all inhabitants of the system to close it, including the viruses, but can they be trusted?

Mainframe begins to crash around them and users from games played break out into mainframe. Matrix meets up with an enemy from his past.

The infected Megabyte merges with Hexadecimal, turning into the energy devouring super-virus Gigabyte. It must be stopped before it gathers enough power to create a portal to the Net.

Megabyte and Hexadecimal are about to take the core, but Mainframe is saved at the last minute by an incoming game cube. However with Bob gone, Enzo is left having the answer the call of the guardian protocol.

As Megabyte prepares to launch a another attack using the newly recovered Hexadecimal, Mouse initiates a project to seal Megabyte's domain inside a firewall. Enzo and AndrAIa face the user in a Toy Story-esque racing game.

Matrix is shocked when he finds Mainframe inside a game cube. Dot is there... Phong is there... even Bob! But why did he and AndrAIa reboot as Megabyte and Hexadecimal? And who is Number One?

Having finally found a system with ports to the Net, Matrix is overjoyed. But it doesn't last long, when access is blocked as the city comes under siege by a team of... guardians?

The Saucy Mare is attacked by a group of degraded sprites riding web creatures, and AndrAia is saved by an old friend.

The traps Mouse once placed to stop the web creatures from accessing Mainframe are now making it difficult for the sprites to return home.

Mainframe is all but destroyed and Bob realises that their only hope lies in the user.

Mike accidently shatters Hexadecimal's looking glass, unleashing a horrible black parasite that infects the virus. Suddenly, all the nulls react, flocking to Lost Angles, covering the altered Hexadecimal until she's became a gigantic mass of nulls, walking around and flattening random buildings.

Enzo and AndrAIa are caught in a tournament style fighting game where they have no control and may not be able to defend against the user.

Matrix and Andraia meet up with Captain Capacitor who promises to help them find Bob as long as they release his crew from the prison in which the guardians have placed them.

The crew of the Saucy Mare enter the web looking for Bob but when a web creature sucks away half of AndrAIa's energy, leaving her in a dying state, Matrix must find the creature so he can save her life.

Matrix and the gang finally return to Mainframe only to discover it has been almost destroyed by Megabyte. We learn what the resistance has been doing all this time and the plan to finally save their home.

Megabyte, now able to shift form, rampages through mainframe, but Bob insists his theories on turning a virus good will work.

Dot manages to convince the binomes of one of Megabyte's sectors to entrust her with their PIDs, so she can register them with the Principal Office. But first she has to get them safely back to Mainframe, which proves harder than anticipated when the virals attack the meeting place. And if that wasn't enough, she keeps getting mysterious flashes of a reality where Megabyte has taken control of the system.

With Dot stuck in a game, heavily depressed and about to give up, Phong decides to take drastic action, sending her into a possible future where she lost the game and got herself and Bob nullified.

The joy of receiving a new upgrade is cut short when it turns out to contain Megabyte himself, who's decided to take a more direct approach to infecting the core.

Megabyte is draining energy from the games to fuel his attempt to breach the Mainframe archive's protective barrier. But when he takes too much, the game crashes and merges with a new one, trapping him and Bob inside the chaos.

Megabyte makes a grab for the core energy, but ends up getting trapped with it inside a corrupt game. Now Bob must keep the game going until he can get the energy back to the Principal Office or Mainframe will shut down when game ends.

Enzo is feeling along since there are no sprites his age in Mainframe. Dot won't let him enter games with Bob and Frisket comes and goes has he pleases. So when a game cube drops on the Diner and he runs to a young female sprite named AndrAIa, he's all too quick to make friends with her. But there's something Enzo doesn't seem to realise about AndrAIa...

Megabyte is trying to turn Mainfraime against Enzo, blocking him from entering the games and smearing his reputation with propaganda. When the young guardian finally manages to sneak past the blockade, it's more crucial than ever that he wins, this time facing Rocky the Rabid Raccoon...

Matrix and AndrAIa find themselves on different sides of a conflict between the mysterious Spectrols and a team of super hero sprites.

The battle for Mainframe begins and Matrix has a final confrontation with Megabyte. Meanwhile, Hexadecimal seems to have gone even more insane but Bob thinks he might be able to help her.