After an outing downtown, Mikey starts behaving strangely – as in super strength, green-slime-spewing strangely. The reason, the Turtles soon discover, is that Mikey has been "implanted" by one of Sh'Okanabo's "gene-seeds". Sh'Okanabo has begun his first test of introducing the seeds into the general population in order to propagate his alien race, transforming ordinary folks into monstrous Kanabo drones! But will our heroes be able to stop him before becoming "implanted" themselves?

While in Cody's trophy-room the Turtles find an old journal written by April and Casey. Feeling homesick they decide to read some of its content...big mistake.