Goodbye and Good Riddance

Goodbye and Good Riddance is the fifty-second and final episode of Ben 10. It is the season 4 finale and the series finale of Ben 10.

Original Airdate
April 15, 2008

Plot
Ben returns home after summer vacation ends, and is told that he must keep the Omnitrix a secret. This is made all the more difficult by Ben's fellow classmates who admire Ben's many alien heroes while completely oblivious to Ben himself. Initially disappointed, Ben gets the chance to use the Omnitrix when Vilgax attacks, yet again looking to take the device from Ben. All four Tennysons (Ben's father helps) fight off Vilgax's drones running amok in the city. When Vilgax appears again, easily fending off Ben, Ben's father suggests leading him into the underground gas line, which they ignite to incinerate the villain. Ben's secret is revealed to the public during the affair, and Gwen ends up transferring to his school. Just when it seems like everything is quiet, Dr. Animo shows up with a mob of mutated animals, which Ben and Gwen get ready to fight.

Debuts

 * Carl Tennyson
 * Sandra Tennyson
 * Ben's Dog (Possibly Sam)

Characters

 * Ben
 * Gwen
 * Grandpa Max
 * Carl Tennyson
 * Sandra Tennyson
 * Cash
 * JT
 * Jamie
 * Principal White
 * Ben's dog (Possibly Sam)

Villains

 * Vilgax
 * Vilgax's Drones
 * Dr. Animo

Aliens used

 * Wildvine
 * XLR8(x2)
 * Diamondhead
 * Cannonbolt

Trivia

 * The episode is possibility what leads to the alternate future of Ben 10,000, when the future XLR8 said to the younger Ben that Vilgax was mutilated and destroyed, that is a high possibility that was from the explosion in the end of the episode.
 * Just like the episode Gwen 10, this episode is non-canon, it is just another "what if" episode, which was revealed in the Ben 10: Pop-up Edition.
 * Despite the fact that this episode is non-canon, Gwen and her family did move into Bellwood.
 * Even though Cash and JT appear they do not give Ben a wedgie, but Ben gave them a wedgie.
 * Many of Ben's alien exploits are mentioned by Ben's classmates, such as Heatblast's burning building rescue (Washington B.C.), Fourarms fight with Kevin on top the Golden Gate bridge (Framed), Wildmutt's battle with Hex in Las Vegas (Tough Luck), Wildvine's battle with Sublimino (Midnight Madness), and Diamondhead at the Little League World Series (The Unnaturals).
 * The music played when Diamondhead is fighting Vilgax's drones is the same music in Ben 10 Protector of Earth.
 * Unlike the sequels of this series, the original series is the only one to feature non-canon episodes.
 * In the begining and end of the episode, its shows the "episode comic book", and in the cover is write #52, as the episode number, even the episode number is 50, because Secret of The Omnitrix counts as two episodes.