Luna Girl kidnaps the legendary lunar moth and without it, no one will be able to sleep tonight. It's then up to the four PJ Masks to stop her and save the lunar moth.
The episode begins at night where everyone is ready to go to sleep while some people are still awake watching TV, having evening snacks, playing their devices or video games, and reading their favorite books. After all the lights in the houses went off, the Lunar Moth flies from the Fantasy Forest over to their neighborhood and then starts to sing an enchanting lullaby as she begins to glow and a shower of sparkles comes out of her fluttering wings.
The next morning, everyone at Disney Junior Elementary School was in a cheery and happy mood after getting a goodnight's sleep and hearing the Lunar Moth's song. Later, the next night, everyone was getting ready for bed but something wasn't right! Nobody heard the Lunar Moth's song that night and nobody seems to have a pleasant sleep after that. Everyone, except Captain Jake, Amaya, Connor, and Greg, was now feeling really cranky the next day at school so they've decided to go into the night to find the Lunar Moth and save her from whoever kidnapped her.
Later, the four PJ Masks have already transformed and have headed straight to the HQ. Owlette then presses the owl glider button to take the Owl Glider since they will be finding the Lunar Moth up above as they head to the first floor and hopped into the Owl Glider and they were off! Owlette flew her vehicle and then used her owl eyes to spot not really the Lunar Moth, but one of Luna Girl's moths flying towards her Luna Lair. Quietly, they followed the moth to it's location and as they arrived, they find the swarms of moths and Luna Girl... And in a glass prison that was the shape of a full moon, was the Lunar Moth!
Owlette lands the Owl Glider onto a lower roof and the PJ Masks hop out of it to sneak to the other building's roof. When they got closer, they saw how scared and miserable the Lunar Moth looked when Luna Girl forced it to sing for her and her moths, but the Lunar Moth was too scared to sing so Luna Girl uses a stick to poke it really hard on the tummy! The Lunar Moth finally gave up and started singing, only in a sad, hurtful tone instead of a happy one.
Annoyed and angered, Cat Boy leaps out of their hiding place before anyone could stop him. Luna Girl pulls out her Luna Magnet, then shoots a luna magnet beam at him. But quickly, Cat Boy jumps up and dodges the beam just in time but it hit Fish Boy, and he was frozen stiff! Then Gekko and Owlette leap into action but the moth swarms stopped them by tickling them, which gave Luna Girl enough time to lift the Luna Moth's prison and fly off as the moths follow her behind her when they stopped tickling Owlette and Gekko.
Angered, Cat Boy scowls at Luna Girl as she gets away with the Lunar Moth. Cat Boy calms down eventually and apologizes to his friends because he was too cranky and that he needed the Lunar Moth's song now to get some sleep. Owlette tells him to not worry and they will get the Lunar Moth back for sure, then the gang heads back to the Owl Glider and they followed Luna Girl.