Mac jumps up onto a large streamer-adorned table in the middle of the library and fiercely stomps a birthday cake in the center of the table. "I WARNED Bloo not to throw me a party," he exclaims angrily. "Every year I tell him NO MORE PARTIES! But does he listen? NO! He NEVER, EVER, EVER, EVER listens! But he'll listen NOW!" The little boy then proceeds to stomp a nearby present and kicks it away. "WAHAHAHAHAHAHAAA!" he laughs maniacally.

"But Mac," says a worried Frankie Foster as she traipses up to him. "This party isn't for you." The little boy is perplexed by this until he sees Bloo entering the room, holding a blindfolded Artie's hand. "SURRPRIII-Whoa," Bloo cuts his announcement off sharply upon seeing the destroyed decorations. "What the heck happened here?"

Scanning the room, Mac quickly spies balloons sporting the number 4 hanging from the ceiling and a poster with a picture of Artie on it adorning the walls; looking down, he observes the demolished cake, bearing the words, "Happy Birthday, Artie" at his feet. As Artie removes his blindfold and gasps in horror, the little boy feels his heart rapidly sinking. "Artie, I-I didn't..." he stammers.

"I was...four yea's owed..." Artie says dolefully, upon which he bursts into tears and runs away. Now feeling truly terrible of what he's done, Mac quickly climbs down from the table and runs toward Artie. "Artie, wait, please!" Before he can reach the door, Mac gently places a consoling hand on the sorrowing little friend's shoulder. "I'm sorry, Artie," the little boy says guiltily. "I never meant to ruin your fourth birthday party. I just...thought the party was for me and I just couldn't bear another one!"

Artie sniffles and brushes the tears from his eyes with his sleeve. "Y-you...don't wike parties, Mister Mac?"

"Well, no, it's not quite that," Mac replies. "It's just that...Well, every year on my birthday, Bloo has given me unexpected surprises on my birthday, and has embarrassed me in front of all of my friends." He then takes a tissue from his pocket and gently dabs Artie's eyes.

Frankie and the friends of Foster's, who had been listening nearby, are amazed by what they've heard. "Bloo was trying to humiliate Mac on his birthday?" Wilt exclaims in shock.

"I...I can't believe it!" notes Frankie.

"Coco!" Coco exclaims.

"It's true," the friends hear a familiar British-accented voice say, upon which they turn to see Mr. Herriman hopping up to them. "Master Mac had informed me of the matter earlier."

"Gee," Frankie says sadly. "If only we had known..."

"I wish there was something we could do to make this up to Senor Mac." Eduardo despairs.

Upon hearing these words, Frankie is suddenly hit with a brilliant idea. "Say..." she muses. "Maybe there is!" She and the friends then huddle and begin whispering the plan to each other. "Ooh, that's wonderful!" "This will be perfect!" "Coco!" the friends whisper excitedly.

"I promise, Artie," a still woeful Mac says. "I'll throw you a new and even better party." Just then, Frankie and the others traipse up to him. "We're sorry, Mac," Frankie says guiltily. "We should have known Bloo was behind this. To make this up to both you and Artie, the friends and I are going to throw a party for both of you."

Upon hearing these words, Mac and Artie's eyes light up. "A party? For us?" Artie says elatedly. "Ohh, thank you so much!" the two cheer happily. "This means so much to us!"

Frankie smiles and gives the two a gentle hug. "You're quite welcome, Sweeties." Mac and Artie smile and blush contentedly.

A worried look then crosses Mac's face. "But what if Bloo tries to mess this one up, too?"

"Don't worry, Mac," Frankie replies reassuringly. "We'll have this part completely Bloo-proofed."

Unfortunately, Bloo, who was listening nearby, ha heard their every word. "So, think they'll get one over on the ol' Blooster, do they?" he says vindictively. "Well, I'll get the better of them, just see if I don't! Nobody messes with Bloo the Bah-uhm, Bloo the Buh-uhm...with Bloo!" Upon this, he quickly runs off.

Moments later, the friends are gathered in the dining room next to a large, streamer-adorned table where Mac and Artie, both of whom are wearing colorful party hats, are sitting. Frankie brings in a large chocolate cake adorned with candles and sits it in the middle of the table, upon which she and the friends begin to sing:

"Happy birthday to you,

Happy birthday to you,

Happy birthday, Mac and Artie,

Happy birthday to you-u-u-u!"

The two smile happily at their friends' kindness; motioning toward the cake, Mac politely inquires, "Artie, would you like to blow out the candles?"

"Yes, pwease. T'ank 'oo." the little friend replies, upon which he takes a deep breath and deftly blows out all of the candles at once. Mac and the others happily cheer and clap.

Wilt then begins to hang the pinata, little knowing that Bloo was hiding inside. As he slowly tugs the rope, the tall friend sings to himself, "Take out the papers and the trash, Or you don't get no spendin' cash, If you don't scrub that kitchen floor, You ain't gonna rock 'n roll no more, Yakkety Yak!" From inside the pinata, a voice replies, "Don't talk back!"

"Huh?" Wilt stops and stares in perplexity, then quickly dismisses the incident. "Mmn. Must have been the wind." From inside the pinata, Bloo breathes a small, silent sigh of relief.

Noticing the pinata being hung up, Mac turns to Artie and inquires, "Say Artie, would you like to try hitting the pinata?"

"Ooh, yes, pwease!" the little replies excitedly, bouncing up and down in his seat.

"Cool!" Mac replies. He and Artie then traipse up to the pinata; Mac takes a blindfold off of a nearby table and gently blindfolds Artie, then hands him a large baseball bat. "Now, the object of the game is to swing the bat and try to crack the pinata open."

"Alwighty." Artie obliges, upon which he reaches back to give the bat a mighty swing. From inside the pinata, Bloo suddenly realizes what's about to happen. "No, n-no, wait!" he stammers apprehensively. Unfortunately for him, his plea comes a bit too late. Artie swings the bat hard and bashes the pinata open, causing Bloo to pop out and go hurtling to the ground, amidst a huge cascade of candy. "WAAAAAAAAAAAAAAAAH!"

As Bloo and the candy hit the ground, a large group of little friends cheer, "YAAAY!" and hurry over to scoop up the candy. As Artie grabs up a big armful of candy, Mac gently places a hand on his shoulder. "Nice shot."

"I hate surprises." Bloo grumbles.

The end.