Michelangelo and Ice Cream Kitty were playing around in Donnie's Lab in Antonio's Pizza-Rama. Mikey was mixing things up with other chemicals and then he decided to add this chemical to the Retro-Mutagen. Donatello found out, and then he tried to stop Mikey, but one drop fell inside the batch and then the Retro-Mutagen was about to explode, but it turn mild. Donnie discovered that this substance made it able for Mutagen to turn into Retro-Mutagen.
- Michelangelo does not remember what he added in the chemical.
- With only one drop of this with the Retro-Mutagen, it can turn a lot of Mutagen into Retro-Mutagen.