Brendan & one of his minions plans to put the Fireside Girls out of business by disguising as Phineas & Isabella. They start by burning down the Lodge, the Clubhouse & the Cupcake Factory & blame the real Phineas & Isabella for it. But little does Brendan know that the Fireside Girls have a secret bunker hidden somewhere, so he creates the fake Fireside Girls robots to kill off the original ones. However, one of the Fireside Girls has to die and it's going to devestate Adam, but who!?