Teenage Mutant Ninja Turtles (2003): Season 4, Episode 25

4 - 25: Good Genes - Part Two

To cure Donatello the Turtles made a deal with the devil aka Bishop. Now they have to retrive a pendant that is supposed to help Bishop in his research. The thing is that the pendant is in the heart of the Foot-building, and Karai won't just hand it over.