The boys help Baljeet express his emotions through music, and form a band to perform at a summer camp concert. Meanwhile, Stacy sets Candace up with Coltrane, and Doofenshmirtz plots to create an army of babies by broadcasting his heartbeat across the city on a speaker.

Dr. Doofenshmirtz gives her daughter Vanessa an assignment to retrieve a container at a mall containing a rare chemical for him to prove she is responsible enough to have her own car, but Perry (who is trying to get it away from Dr. Doofenshmirtz), Baljeet (who wants to use it in a science project), and Candace (who thinks the item is a lantern she can give to Jeremy) are also trying to get the capsule.