However, Viral, who had survived her defeat in the previous season, hacks into the time window, taking control of it and sending the Turtles, Splinter, and Serling (who accidentally fell in) to various eras in an attempt to kill them.
In the season's finale, Splinter is recompiled and returned to his adopted sons, who decide to celebrate April and Casey's wedding.
Dozens of the Turtles' closest allies attend the ceremony- Angel, Usagi, Leatherhead, Karai, Dr. Chaplain- which is violently attacked by the Foot Clan, led by the Shredder, who has finally entered the physical world.
Additionally, the Rat King and Renet watch from a distance, whereas the Daimyo, the Ultimate Ninja, Agent Bishop, and Cody observe the wedding through either technological or magical means.
Following their intentions to return the characters to the present day and adapt a tone similar to the recent TMNT movie, 4Kids pitched a revamp of the series to Peter Laird codenamed "Superworld."
[2] On October 24, 2007, Steve Murphy confirmed on his blog that Playmates, Mirage, and 4Kids had firmly agreed on the new direction, which will take place in the continuity of the 2003 series and use the "more realistic aspects" of the aborted "Overload" pitch, with character designs similar to that of the 2007 TMNT movie.
[4]Further info was revealed in December 2007: When the Turtles return from the future to their present time, Viral interferes causing Master Splinter to get trapped in cyberspace, bits of his data code scattered all throughout the digital domain.
The Turtles must find a way to access the virtual realm so they can gather Splinter’s code and save their beloved father before he is lost to them forever.
Having escaped to the real world, Cyber-Shredder hacks into New York's power grid and takes control of every electronic device in the city, effectively conquering it.
Starting on March 7, 2009, a series of 13 shorts, called "chapters", ranging from 90 seconds to two minutes in length, began airing on The CW4Kids during episodes of TMNT: Back to the Sewer and Chaotic: M'arrillian Invasion.