But Phineas,Ferb, and Isabella aren't backing down with out a fight, and they're not alone because Sonic brought along Shadow and Silver to help them! Together Phineas,Ferb,Sonic,Shadow,Silver,and all of Phineas and Ferb's friends and family (except Linda and Lawrence) are gonna stop Evil Super Sonic from not only destroying their world, But both the Sonic and P&F Universes! Meanwhille Doofenshmirtz tries to make a Broadway Musical.