This special episode begins with us joining our friends outside, looking at a blue moon. Some sort of glowing orb appears and Blue catches it. It turns out to be a fairy, who introduces herself as Moona, the moon fairy. Moona tells us Blue's story, saying that Blue was born with a group of puppies, but wasn't like the other puppies. She liked to do things that the other puppies didn't, like reading. There was also something else special about her, she was born with a key, although she didn't know what it was for. She says that everything will change today: with the blue moon lighting the sky, Blue will be able to unlock her greatest gift. She asks if Blue is up for the adventure of finding her greatest gift and Blue agrees. Moona heads into the Blue's Clues house and we follow her. As we follow her into the house, we find that she's led us to Blue's stuffed toy, Polka Dots. It turns out that Polka Dots has the key that Blue needs to unlock her greatest gift. The only thing is, Blue doesn't know where the lock is. Moona isn't going to lead us to this one, so we have to help Blue and the rest of the characters to look for it. We find a lock on the toy chest, but the Key says that it's way too big, like a big hole that he could fall into. We go outside to the patio where we find a lock on a bench, but this one's too small too. Joe puts on a silly hat, hoping to find a lock on it, but comes up empty. Another lock is found on a grandfather clock, but that one is much too narrow. Blue begins to despair, but both Joe and Periwinkle encourge her not to give up. Mr. Salt and Mrs. Pepper help out too by providing some cookies that they made to cheer us up. We keep looking, under bananas and even in the phone. Joe picks it up and asks if Lock is there, then decides that he has a wrong number. Finally, we find Polka Dots and a sparkling chest. Blue tries the key and it's a match. Moona appears, animating us into... Blue's Room! Moona tells Blue all of the great things about her room, saying that the greatest thing about it is that she can talk. Blue tries it and is surprised to find that she can, indeed, talk. She says that there's so many things she wants to talk about. She asks our what our favorite color is, saying that hers is blue. She likes bluebirds and blueberry pancakes. She thinks it would be fun to hold a party celebrating our favorite colors. So she goes to get some juice. Hers is blue and she says it tastes like blueberry muffins. She wonders what ours tastes like. Polka Dots shows up and suggests that we play with Doodle Board. We play a game with him where he doodles part of a picture and we try to guess what it is. We then meet Frederica, who says she prefers to be called Fred. She says that it's her birthday and Polka Dots warns Blue that Fred likes to pretend it's her birthday. We then go visit Dress-Up Chest and Blue has fun dressing up as a firefighter, a movie star and a doctor. Next, we meet Roary the dinosaur, who enjoys practicing his roaring and dancing. The fun's not over yet - we meet "Boogie-Woogie" and play a game with him where we get get down when he says "Boogie" and plays music and freeze when he says "Woogie." Blue says that there's so much to do in her room. The best thing she loves about it is that she gets to spend time with us. Finally, a clock chimes, which means that it's time for Blue to leave her playroom and return to Joe. Once back in the Blue's Clues house, we tell Joe about Blue's greatest gift, which he thinks is really neat. He bids us goodbye and that's all for now.