Ready for the Bettys, I Scream, You Scream

Ferb and Phineas accidentally discover Perry's secret lair and are thrust into a spy mission of their own. Meanwhile, Candace travels on a tour bus with a girl band called "The Bettys"
Phineas and Ferb make the biggest ice cream maker for Isabella after her tonsils are taken out. Doofenshmirtz's daughter, Vanessa, spends the day at his lair and tries to convince his ex-wife that he's evil.