Let the Frightingale Sing! is the 26th episode of Season 16.
Gekko must overcome his fear of the Frightingale when Night Ninja adopts it and uses it's singing to scare him and the PJ Masks from their headquarters.
The episode begins at Pirate Island's hideout where Connor, Amaya, and Greg are staying with Captain Jake, Izzy, Cubby, and Skully for a sleepover. They were enjoying themselves to treats, music, and even telling scary stories like the one about the Frightingale, a scary bird that sings an eerie song in the Fantasy Forest to scare off animals. It scared Greg and Cubby a lot, so Connor had to calm their nerves by asking Captain Jake to tell everyone a different story.
Nodding, Captain Jake begins to tells another story when the PJ Masks' wristbands began to beep, which meant that someone is trying to break into the PJ Masks' headquarters again! Quickly, Connor, Amaya, Greg, and Captain Jake transformed into the PJ Masks and waved goodbye to Izzy, Cubby, and Skully before they went to their HQ and check out who or what was trying to attack.
But when they arrived, there was no one in their HQ. All except a strange and scary song that brought a chill to Gekko's spine, but Catboy, Owlette, and Fish Boy stayed static as they listened to where the song was coming from. Meanwhile outside, Night Ninja and his Ninjalinos were watching through a tablet while inside, a Frightingale that was wearing an onyx choker with a spying camera was perched on a vine on the ceiling.
Night Ninja's plan was going according to plan. Once his new Frightingale pet sings it's song in the PJ Masks' HQ, the PJ Masks will be so scared to think that their HQ is haunted and then they'll be running home safely. Then, he will have their HQ all to himself. As Night Ninja let out an evil laugh, he orders the Frightingale to sing it's song but it refused. Then growling, Night Ninja presses a button on a remote to make the collar around the Frightingale's neck hot and burn it's feathers, that it had no choice but to do his master's orders.
When it sang it's scariest song, Gekko jumped and ran behind Fish Boy who gave him a questioning look. When Fish Boy asked Gekko if he was okay, Gekko replies in a shaky voice that he is fine but Catboy and Fish Boy both knew that he wasn't, until they heard the Frightingale's song again and as they heard, Catboy decides that he and his friends should split up and find whatever was singing that beautiful but strange song.
But as one of the PJ Masks was about to go to each different floor of the HQ, Gekko stayed close to Fish Boy and said that he doesn't like the idea of going alone. With a sigh, Catboy decides to change the plan; they'll go into groups of two; Gekko with Fish Boy and Owlette with Catboy. As they parted into two teams of two, the Frightingale heard Night Ninja's voice from it's collar as it heard him say to go to each different HQ room and keeping singing it's song without being found by any of the PJ Masks.
Meanwhile in Gekko's HQ room, Fish Boy and Gekko were searching while Gekko was trying to be brave, even if it was for a second. Just then, the Frightingale perched itself on a vine and began singing again, then Gekko was frightened by the song again as it got louder and louder. Fish Boy turns to see Gekko shivering and ducking while covering his ears, so he walks up to his friend and tries his best to comfort him.