Bubbles floated in the empty grid of the Danger Room. Blossom and Buttercup watched her through the glass of the control room with anticipation while Professor, wearing the goggles, fiddled with the computer. He spoke to her through the microphone in the console.

"Now, Bubbles, concentrate on channeling all of your energy to the tips of your hands and feet. Don't hit your target directly or you'll go right through it."

"Yeah, Bubbles, sort of come at 'em sideways!" Buttercup encouraged her. "Like this!"

She did a spin move, kicking out one leg sideways, then brought her opposite arm back across her body in a side-swiping karate chop that smacked Blossom across the side of the head and knocked her to the floor. Bubbles giggled.

"Oooops! Sorry!" Buttercup apologized.

Blossom stood up, rubbing her head. "The mosquitoes are rather pesky this time of year, aren't they, Professor?" she said, grinning at her sister.

Buttercup grinned back. "Touche, Blossom. Okay, Bubbles, let's see you smoke this sucker!"

"I'm ready, Professor, an' don't give me no baby monster, neither!"

She was remembering to look at him when she spoke, and he was getting better at reading her lips.

"Well, honey, I think we should start you out with something-"

"NO!" she yelled. Her pale blue image tripled in size and then shrunk back to her normal proportions. Blossom and Buttercup could feel her anger come right through the walls into the room with them, in the form of an energy wave. The effect was rather frightening.

"Uh, okay..." Professor said, a bit nervously, doing some more adjusting.

"It shouldn't be THAT bad, Professor." Blossom said. "It can't hit what it can't see!"

An enormous red beast appeared in front of Bubbles on the holodeck. Its massive mouth opened, letting out a fearsome roar and displaying uneven rows of ugly, razor-like teeth. Three fingers on each hand showed off long, dagger-like nails that matched the much bigger ones on each of its three-toed feet. It had a long tail with a club-like end, covered with short, spiky points. Its huge head tapered to a mean-looking black spike at the top. It balefully glared at Bubbles with pale yellow eyeballs and sickly green-colored irises. It seemed to be looking directly at her.

"Right, Professor?" Blossom asked.

Without warning, the creature roared and backhanded Bubbles against the far wall of the Danger Room. She disappeared through it.

"Bubbles!" Blossom screamed. Professor held up a restraining hand.

"Professor, how did that happen? When I hit her, my fist went through her into the wall!" Buttercup asked.

"So THAT?S how that hole got in the bathroom wall!" he thought. "Because even though she?s a ghost, with her tensed up like she is, she?s like a baseball."

"Wow! She got knocked right out of the park!"

"Don?t worry. She should be sliding into home?right about...now!"

Bubbles popped through the wall, her face a mask of fury.

"You didn't want a little baby monster, Bubbles. I programmed it to be able to detect your energy. It can see you just fine."

"No problem!" she growled.

"Whoa!" Buttercup exclaimed. "A REAL monster won't be able to do that! If she beats this, she'll be able to beat anything! This is GREAT!"

"C'mon, Bubbles! You can do it!" Blossom yelled.

Bubbles angry face turned into a wicked sneer, and she flew, zigzagging, through the monster's legs. Just as she got between them, she shot out her left leg toward the creature's right knee. It struck a glancing blow and the monster roared with pain and looked down to try to find its attacker. She quickly came around from behind it, and with it still looking down, she gave it a series of quick chops and kicks. She learned quickly. Each thrust gave the beast pain and it backed away, holding up its huge hands. Now that she knew it could see her, she watched the eyes. She sailed around behind it, keeping low. It sent a punch sailing toward her that narrowly missed, and it left the beast off balance. Behind it, now, she gave it a sharp, glancing kick behind its already damaged right knee, and it started to buckle. Using both of her hands, she swiped them against the tip of the monster's tail, and it whipped around the beast's legs in a blur, with the spiked club smashing into the left knee. It was now immobilized and could only flail its arms as it roared in frustration. Bubbles now channeled all her energy to the outermost surfaces of her ghostly body, and she flew under the monster. With that hard outer shell of energy surrounding her, she was able to effortlessly lift the massive creature and slam it to the ground.

Her sisters stood, open-mouthed, watching her in action. With the beast finished, it winked out of existence and the bare grid of the Danger Room reappeared. They zipped down to congratulate her, forgot her transparent nature one more time, and were about to bang heads again when she held up her hands and stopped them. They both bounced off a few feet.

She beamed happily. She had done it! Her stunned sisters moved cautiously toward her and carefully embraced her this time. It was amazing, and wonderful. She could actually touch and feel them and they, her. It wasn't quite the same as flesh and blood, but better than the hollowness she was afraid she was stuck with until Professor could figure out a way to get her back.

They joyfully exchanged high-fives with one another.

"YAY!"

Professor gave them a group of strange-looking creatures that they could all fight together. All of them were programmed to be able to 'see' Bubbles. The Powerpuffs were a smashing success. If a call came in now, it was very likely that anything they faced would only be able to see two Powerpuff Girls. Bubbles could probably beat it all by herself. They were very pleased with themselves, and excited.

"Bubbles, you are awesome!" Buttercup enthused.

They looked up to see Professor smiling down at them. Bubbles smiled back at him.

"Well, until Professor can fix me, I don't have a problem bein' a ghost, bustin' bad guys!"

Professor's eyes flew open upon hearing those words, and he started to dash out of the control room. He raced for the lab.

"Oh my gosh, I can't believe I forgot to call! Girls! Don't go anywhere! I've got to make a phone call!"

Surprised, they watched him go. Together, they shouted "Who you gonna call, Professor?"

The five of them were back in the lab. The girls stared at Professor, not believing what he just told them.

"No way, Professor! Those guys aren't real!" Buttercup exclaimed.

"Professor, 'Ghostbusters' was just a movie!' Blossom said, confused.

"Yes, Blossom. It was a movie, but it was based on a true story."

"No!" Bubbles screamed, horrified. The pale blue tears fell from her eyes again, evaporating into nothingness. "I don't wanna get put in one of them little boxes! I never slimed anybody!"

"Calm down, dear. A lot of that was exaggerated for the movie. The writers thought the truth was too boring."

"Huh?" Blossom asked. "You mean there's no-"

"Nope. There's no such thing as ectoplasm. Ghosts are energy, just like I told you, Bubbles; they're not blobs of disgusting slime. There's no proton packs or ray guns."

"So, how do you know about these guys, Professor?" Buttercup asked.

"I knew them from college. They sold the movie rights to their story and used the money to continue their research. Although," he said, remembering with a smile, "Venkman wanted to move to Vegas and start a lounge act!"

"Venkman!" Blossom said. "That was one of them!"

"Yep. The movie used their real names. Peter Venkman, Ray Stantz and Egon Spengler. Pete was always more of a con man than a scientist. Lousy poker player, too." He pointed to the goggles on his face. "That's where I got these. Boy, was Egon mad!"

"Wow!" Bubbles was amazed.

"Tell us more, Professor!" Buttercup urged him.

"Egon developed these but never had a chance to find out if they worked. He's a brilliant scientist, but I always thought he wasted his talent. I guess I was wrong. Ray's pretty good, too. Peter was always the smooth talker. He never really believed in ghosts, in fact, never believed in much at all, except that you could make a buck off of those that fell for whatever you were pitching. Turned out that Egon and Ray were right, though, and Pete made them all a ton of money."

"How does it work, Professor?" Blossom inquired.

"Well, when Egon's theory proved true and he uncovered the science behind what ghosts are, he came up with a device to trap their energies and restore them to the bodies they came from. It worked. The hauntings ended and the tortured souls were able to find peace."

"YAY!" they shouted again.

"So, they're coming to fix Bubbles?" Blossom asked excitedly.

He sighed and sank lower in his chair. "No."

They were crestfallen, especially Bubbles. "Why?" she asked, in tears.

"You see, all of their work has been done with ghosts that were around for a long time. Once they identified the person that the spirit belonged to, they simply reversed the trapping process at the grave. It did what the spirit could never do on its own, reunited the two. That's what you tried to do, Bubbles. It doesn't work. I talked to Egon. I told him everything that happened. Unfortunately, they've never been successful in restoring the spirit of a recently deceased person to its body and bringing them back to life."

"Great. Just great!" Buttercup griped. "So what made you think YOU could do it, huh?"

"Because of my belief that you girls were different. You see, Bubbles, you aren't like any other ghost. Those ghosts can't go back to their living bodies, because they're long gone. But they CAN be reunited in the afterlife. Because you three are tied together, you have no place to go until you all go at once. So if you aren't restored to your body, you'll have to stay like this until your sisters join you. I meant to call Egon earlier to get some advice, but I forgot until you reminded me, Bubbles."

"So, now what, Professor?" Blossom wanted to know.

He stood up, a determined look on his face. "Girls, I haven't given up yet! Bubbles, come with me. I think if I can determine your exact frequency, I can still do it. We just have one problem, and that's how to preserve your body until I'm ready to give it a try."

They all looked over to see her small, pale form, still slumped peacefully in the beanbag chair. Buttercup floated over and sniffed.

"So far, so good. Hey Bubbles, except for your skin, you look like one of those giant stuffed dolls of us!"

She and Bubbles giggled. Blossom jumped out of her beanbag.

"That?s it! Professor, I know how we're gonna keep her nice and fresh! Come on, Buttercup!"

Professor watched them fly off, wondering what Blossom had in mind. He turned and started to walk toward his desk.

"Come on, sweetie, let's get started."

He turned to see if she was coming, and just about jumped out of his skin. Bubbles' body was floating in front of him, slumped over. Bubbles' ghostly image was supporting it in the air, and she was laughing. He frowned.

"Don't scare me like that!"