"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."
In the backyard, Tasha holds a rolled-up piece in her hand and explains to the audience that she is a great queen. The backyard transforms into a castle, and Queen Tasha sits on her throne and calls for Uniqua.
Uniqua comes in and Queen Tasha says she has to deliver a very important message to King Austin; if she succeeds she will become a knight. 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 this, she has to be brave, smart, and strong. Uniqua agrees to this and goes on her way.
Once she reaches the Forest of Mist, Uniqua hears a moaning noise and wonders if it is the legendary Moose of the Mist after hearing a moan. After encountering the moose (who is really Tyrone), she realizes that he is not so scary after all and invites him to join her on her quest, which he gladly accepts.
A short while later, Uniqua and Tyrone come across a large gate which Pablo is guarding. Initially, Pablo refuses to let them through, but he decides to help them when they explain that they need to get through to deliver a message. They try pushing on the gate, but it does not open. Uniqua suggests pulling on it instead; this method works, and the three friends continue on their way.
Afterwards, they come to the Stinky Swamp, where they try to cross the murky lagoon by walking on the rocks. When they near the other side, a large slab of rock sits right in their path and the rock they are standing on starts to sink. Uniqua pushes on the slab and it topples over, allowing them to cross, but then it starts sinking as well. The three Backyardigans just barely manage to make it to the other side.
Finally, the trio arrives at King Austin's castle. They go inside the castle and encounter the king, who asks why they are here. Uniqua tells him about her journey and says that the queen sent her to deliver a message. The king is impressed with what he hears and awards the adventurers with knights' caps, thus making them knights.
King Austin reads the message that Queen Tasha wrote; it says that he and the other Backyardigans can come over for pretzels and juice. The castle transforms back into the backyard as they join Tasha and go inside Uniqua's house.