Uniqua the Pink is sent by Queen Tasha to take a message to the Castle of King Austin, who shall make her a knight if she succeeds. Along the way, she meets the Moose of the Mist and The Guardian of the Gate, who join her quest in hopes of becoming knights too.
Tasha is first seen in the backyard. She has a rolled up piece of paper in her hand. Tasha explains to the viewer how she is a great queen, and how queens are always right. She sings the song Queens Are Never Wrong. Queen Tasha journeys into her castle, which the backyard transforms into. She walks up to her throne and calls for Uniqua.
Uniqua comes in, bows, and asks politely why she was called. Tasha answers by telling her that she has to deliver a very important message to King Austin, and will become a knight if she succeeds. Uniqua tells her that it will be easy for her and tries to walk out the door to begin the task. Tasha warns her that she will have to get through the forest of mist, past the guardian of the gate, and through the stinky swamp to complete the job, and in order to do that, she has to be brave, smart, and strong. Uniqua agrees to take responsibility.
Uniqua starts off through the misty forest. She sings the song A Message, A Message. Uniqua starts to think that she will run into the legendary Moose of the Mist after hearing a moan. She walks slower. She hears the moan again. A mysterious figure is spotted. The figure moans. Uniqua knows who the shape is - the moose! The Moose of the Mist starts to run. Uniqua runs as well. After a lot of commotion, the two collide with each other.
Tyrone looks at Uniqua. He starts to feel better after knowing that she does not look scary. Uniqua is glad to finally know what the moose looked like. Tyrone tells Uniqua that he was scared of her, and tried to run away. Tyrone also asks Uniqua why she is in the forest. Uniqua answers, telling Tyrone that she is on a quest to deliver a message to the king, and will become a knight if she does so. She also tells Tyrone that he could join her and become a knight as well. Tyrone accepts. They sing a duet of the song A Message, A Message as they venture through the forest.
Along the way, Tyrone asks how they will get to the king's castle. Uniqua tells him that they will get past the guardian of the gate and go through a stinky swamp to get there. Tyrone is frightened. Uniqua asks why. Tyrone shows her what is up ahead....a large gate guarded by a blue penguin, Pablo. The two tip-toe forward.
Pablo, the gate's guard, sees Tyrone and Uniqua. He asks them why they are here. Uniqua tells Pablo that Queen Tasha ordered her to deliver a message to King Austin. Pablo accepts the answer. Uniqua asks him if he could open the gate, and Pablo pushes with all his might. He cannot open the wooden gate. All three of the friends push. It doesn't work. They all think about why it isn't opening. Uniqua has an idea - they haven't tried pulling!
Uniqua, Tyrone, and Pablo start to pull on the gate's handles. It opens wide. Uniqua tells Pablo that he could join Tyrone and her and become a knight if they all complete the task. Pablo agrees. They start walking. They sing another version of A Message, A Message. After a long while, they come across the swamp. It is bursting with bubbles and slime.
They all sing P. U. as they cross the few platforms of rock floating above the swamp. A giant boulder is in the way of getting to the end, and the rock that the three Backyardigans are on top of starts to sink. Uniqua pushes with all her might at the boulder, and it rolls off, making a path for Uniqua, Pablo, and Tyrone to cross. They all jump across.
In the distance, Uniqua sees King Austin's castle. They all start to run, in order to get to it faster. They ring the castle doorbell. King Austin opens the door and greets the three. He asks why they are here. Uniqua answers by telling him that the queen sent her to deliver a message, and that he would make all three of the questers knights if they did so. King Austin, Pablo, Tyrone, and Uniqua sing The Ballad of the Brave Pink Knight. Austin lets the adventurers become knights and hands them each a knight's cap.
Austin reads the message. It tells Austin that he and the other Backyardigans can come over for a snack - pretzels and juice. The castle transforms back into the backyard. The five characters, including Tasha, sing the end song and head to Uniqua's house. Uniqua opens the previously closed door, and yells the royal fanfare: "Dah-dah-dah-daaaaahh!"