In "Candace Gets Busted", when the parents go on a trip, they leave Candace in charge of the house. She calls some of her friends for a small get-together. It doesn't end well.
The boys build a biodome to help the Fireside Girls. In "Canderemy", Candace's day with Stacy is complicated when, thanks to Dr. Doofenshmirtz, she is fused together with Jeremy.
Candace uses boots that Phineas and Ferb invent to be in two places at once. / A retiring train conductor inspires Candace to become determinedly lackadaisical.
Phineas and Ferb have become boring, and Perry fears he knows how. Doofenshmirtz stresses from Vanessa walking in on a conversation where he sounded like he'd rather have a son.
Candace is bitten by a bat. Phineas and the gang wind up in the best haunted house ever. A mad scheme leaves Dr. Doofenshmirtz adversely affected by the full moon.
Phineas and Ferb decide to create their own language - Ferb Latin - and later end up creating a hybrid race while addressing a potato famine caused by Doofenshmirtz.
The boys decide to put on a traditional family Christmas special featuring their family, friends and a few very special guests, including Kelly Clarkson.