The Mad Nightmare

Ben's country cousin Clyde Fife wants to become a hero like Ben.

Master Kundo, Rook's former teacher is willing to save Revonnahgander traditions at any cost by preventing Rook's sister, Rook Sharr from going to the Plumber Academy so she wouldn't be able to become a Plumber.

Charmcaster attacks Gwen at Freakin' University, wanting to obtain Hex's mystical Staff of Ages through any means necessary, while Kevin and Rook try to make Kevin's car completely indestructible so that nothing can destroy it.

After Mr. Baumann, the grouchy storekeeper, realizes from Ben that his temper comes from being lonely he starts soul-searching. Eventually he stumbles across a secret not from this earth.

When Ester invites Ben (who brings along Rook to the former's dismay) to a museum exhibit displaying alien artifacts, they encounter Ben's former crush Kai. When Ester discovers their relationship she immediately becomes jealous of her. The four of them are forced to team up, however, when a priceless exhibit that Kai put on display is stolen. Chrono Spanner also reappears again, this time trying to convince Ben that he's "destined" to marry Kai, to Ester's chagrin.

Fistrick orchestrates a series of robberies while wearing ID masks programmed to make him and his compatriots to resemble Ben. When the real Ben discovers what's going on he decides to go undercover with Rook's help and investigate Fistrick's workout gym to find out what's going on. As this is all happening, Ben is struggling with his obsessive cravings for chili fries and meatball subs.

With the help of the con-artist Simian, Argit starts a secure transport firm called "Argistix Securities" employing a group of Techadons as workers. Ben immediately becomes suspicious of Argit's business, considering the latter's history.

Pa Vreedle reunites with Ma for all-out, total cosmic destruction! Meanwhile, Rhomboid and Octagon tries to impress Ma and Pa Vreedle like Isosceles and Parallelogram Vreedle always does.

A dangerous Chronosapien named Maltruant attempts to obtain total control over the time-space continuum with the help of an old relic called the Key to Time; Ben 23 is sent by the Azmuth of his dimension to Ben Tennyson's dimension in order for the latter to act as a "mentor" to the former.

With the help of Dr. Psychobos, Ben 23 and Ben Tennyson successfully stage a breakout and a revolution in Mad Ben's labor camp.