During a sleepover with Marinette, Alya punishes her twin sisters, Etta and Ella, who get akumatized into monsters that multiply when they eat.
The supervillain Sandboy uses his powers to turn the nightmares of Parisians into reality, forcing a Tikki-less Marinette to intervene.
A rock star is scheduled to visit the bakery owned by Marinette's parents, but his overwhelmed personal assistant is akumatized by Hawk Moth.
Alya's older sister Nora becomes akumatized by Hawk Moth into Anansi, an enormous spider-woman hybrid named after an African folktale.
Angry over his perception that Marinette and Nathaniel humiliated him, fellow student Marc becomes Reverser, who is determined to get revenge.
Hawk Moth akumatizes Max's best friend and pet robot, Markov, into Robostus, a raging techno-threat with the power to bring inanimate objects to life.