S04E14 - Son of Return of the Fly II
Synopsis
The Turtles try to assist a scientist, Herman J. Melish, who is being chased down by two men trying to get their hands on an invention of his energy generator crystal. The crystal slips away and drops into the sewer.
Baxter Stockman, marooned in some weird dimension with his alien computer, Z, manages to return to Earth and find the energy generator. This generator can turn energy into material objects. Z uses the generator to make himself a body. After this, Baxter and Z come up with a plan to get revenge on Shredder. They head for the Channel Six building, planning on taking it over. They anticipate that the Turtles will try to rescue April, and when they do, Baxter will capture them to use as bait to get Shredder. Their plan works just as they had hoped.
Baxter captures the Turtles and Z sends out a message over the air telling Shredder to come and get the Turtles before Baxter beats him to it. Shredder, who is on Earth looking for a super computer that Krang has tracked to the Chan