Elly, Tash, and Sierra are back for another Flip-Flop Club adventure! It's time for the Sunday Island Music Festival, and stages, tents, and ice-cream stands cover Melody Meadows. The headline act is being kept top-secret, so when the three girls discover that it's none other than their favourite girl band, they're buzzing with excitement! Especially because the band will be performing on stage with the winner of the Tomorrow's Stars competition, which Elly, Tash, and Sierra have entered! If the girls can just get their dance moves in time and their singing in tune, could they be up there on stage with the stars? But all is not well at the festival. There's a big problem that could ruin the whole thing for everyone, and only Elly, Tash, and Sierra know about it. Will they be able to help before it's too late?