It was a clear sunny day in Townsville Park, where the city had gathered to celebrate the Powerpuff Girls' 13th birthday. As per tradition, all the Girls' friends, family and fans came out to give presents and extend their gratitude to the city's heroes and protectors, Blossom, Bubbles and Buttercup. After a couple hours of mingling with their guests, the Professor called the Girls to blow out the candles on their enormous birthday cake.

"Happy Birthday, Powerpuff Girls!" the citizens of Townsville exclaimed in unison. Taking care not to launch it over the horizon as they'd done numerous times before, the Girls toned down their super breath, made their wishes and extinguished all but three of their candles, one pink, one blue and one green. Bubbles looked at the remaining candles and felt an ill omen.

"That's… not a good sign."

"Don't be so superstitious, Bubbles. We took precautions this year." Blossom pointed to their pile of presents. Remembering past instances, the Girls had gone through them and separated out any that came from villains. The suspicious-looking presents were contained behind a forcefield the Professor rigged up. Those that remained were placed on a picnic table.

"Yeah, we'll be fine." Buttercup agreed as she blew out the remaining candles. "Blossom's got the right idea. Let's go open presents!"

"Can we, Professor?" Bubbles asked her dad.

"I suppose you girls have waited long enough. Go ahead, but be careful." Professor Utonium warned as he cut the cake. Each girl took a slice as they made their way over to the present table. The Professor continued passing out slices to the guests.

"Alright, let's open… these… presents…" Blossom trailed off as she heard three streaks of light touch down behind her. "Oh, you've gotta be kidding me!"

The Powerpuff Girls turned around to see their evil male counterparts, the Rowdyruff Boys, Brick, Boomer and Butch. Blossom and Buttercup locked eyes with Brick and Butch, ready to fight as soon the Boys tried to pull something. Bubbles, on the other hand, put her head down and started fidgeting right after she saw Boomer, who also avoided eye contact with any of the girls.

"Afternoon, ladies." Butch quipped sarcastically.

"Oh, great, it's these jerks. What are you doing here?" Buttercup groaned.

"What do you mean, 'these jerks'? And you do realize this is a public park, right? We just happened to be in the area." Brick retorted.

"Please. This was clearly our birthday party." Blossom gestured toward a large banner that read 'Happy Birthday, Powerpuff Girls!'. "Do you really expect me to believe you're not here to mess with us?"

"Enough of this! You here to pick a fight or what?" Buttercup scowled at the boys and raised her fist. Butch cracked his neck and put his fists up in response, awaiting Brick's order to attack.

Brick paused for a moment. He noticed Boomer was awkwardly staring off with his hands behind his back. His unfocused behavior wouldn't be of any help. Brick remembered their last fight with the Girls and how Boomer had failed them. Despite Butch being as eager as ever, the Boys' leader decided that risking a repeat of that disaster wasn't worth the trouble.

"Nah, I'm not feeling it today. You girls enjoy your birthday. Maybe we'll attack tomorrow. Or maybe next week. My schedule's pretty open." With that he turned and walked away, gesturing for his brothers to follow. Butch grumbled in disappointment as he swiped three pieces of birthday cake and went to join his brother. Boomer tried to say something, but just went with the other two boys, leaving the Powerpuff Girls alone.

"What was that all about?" Buttercup asked with a mixture of frustration and confusion.

"First time we see them in months and it's at our birthday party. What are the odds?" Blossom asked rhetorically. "Oh well. They probably just wanted to steal some cake."

"So do we go after them?"

"No, there's enough for everyone. Plus I don't want to give them the satisfaction."

"Speak for yourself. I wouldn't mind punching Butch in the face a few times. Or in the…"

"Easy there, Buttercup." As Blossom quelled her sister, she heard another voice coming from the crowd. "What is it now?" Blossom and Buttercup turned to see three overgrown protozoans brandishing wiffle bats at the other guests.

"Nobody move, see! We're here to commit the greatest crime in the history of Townsville!" yelled their leader.

"Oh, it's the Amoeba Boys." Blossom chirped. "We should go say hi to them."

"Sure." Buttercup agreed and turned to her other sister. "You coming, Bubbles?" Bubbles hadn't said anything since the Rowdyruff Boys showed up, and now she was looking off in the direction the Boys had fled. Buttercup tried again to snap her sister out of her daze. "Bubbles? Yo, Bubbles!"

"Hmm? Oh, yeah, coming."

As she turned away, Boomer quickly returned and approached the table with the Girls' pile of presents. He took out a small box wrapped in blue paper and placed it in the pile. "Happy birthday, Bubbles." he whispered. Then he flew off to rejoin his brothers.