Journey to the Center of Kenzi is the 9th episode of Season 31 on Disney and the 23rd on Nickelodeon. Kenzi accidentally swallows a miniscule time bomb that Doofenshmirtz has sent to destroy Perry. It's up to Phineas, Ferb, and the gang to retrieve the bomb before Kenzi explodes. This episode also has a guest voice actor of Chris Rock, who plays the manager at the bomb factory.