A magician named Hex, whose powers come from mystical charms, is defeated by Ben using XLR8 and a little help from Gwen and Grandpa Max. Afterwards, XLR8 takes all the credit for the victory and even gets one of Hex's charms as a souvenir. When Gwen complains that Ben is getting all the glory and recognition, as well as all the cool stuff, he gives her the charm he got from Hex. The charm gives Gwen perfect luck in everything she does, and she becomes her very own superhero, Lucky Girl. Unfortunately, her luck has a price, and Ben is the one who ends up paying for it.

When Councilwoman Liang attempts to redevelop the downtown area, the demolition efforts disturb a man named Clancy, who has the ability to control insects. Meanwhile, as Ben stops a criminal as Upgrade, he spots at a nearby ice cream truck. When he climbs inside to get a snack, he gets himself locked inside and ends up catching a cold. The virus binds with the alien DNA in the Omnitrix, causing side effects, and weakening his normally powerful forms. On top of that, Clancy kidnaps the councilwoman and threatens the entire city with a meltdown at the nuclear power plant. Now, Ben must save the day while dealing with the strange side effects in his alien forms.