As Siren comes up with an idea to take advantage of Cure Muse' appearance, Hibiki and Kanade continue to struggle in their hunt for her identity. Meanwhile, Muse allegedly calls out Hibiki and Kanade, but in reality, it is Siren who steals the girls' Cure Modules and throws them into the sea. However, they are saved by the real Muse, who reveals the fake. Siren creates a Seaweed Negatone, while Hummy recovers the girl's modules so they can transform.