With D.W. hanging over his shoulder, Arthur raced down the stairway after Francine and Greta. "Why does the world need saving?" he asked loudly.

"If human scientists try to split the magic particles in my horn, they could cause widespread devastation!" answered Greta as she leaped down three steps at a time.

The four children finally reached the hotel lobby and saw Mr. Baker rushing through the revolving door exit, Greta's horn in his hand. "There he is!" cried Greta. "We have to stop him!"

They hurried toward the exit with all the speed they could muster. "Why didn't you tell us about this until now?" asked Francine.

"I never imagined anyone would use the horn for other than selfish purposes," Greta replied.

When they arrived on the sidewalk outside of the hotel, Greta pointed to the right. The others looked and saw Mr. Baker pulling away from a parking meter in his beaten-up gray Oldsmobile.

Greta glanced around desperately, then smiled with relief. "A taxi!"

Indeed, a taxicab sat next to the curb less than half a block away. Greta immediately rushed toward it, waving, while Arthur, with D.W. still draped on his shoulder, and Francine followed.

Then Francine was hit by an idea. "Arthur, give me the horn!" she requested. Arthur quickly pulled D.W.'s unicorn horn from his pocket and handed it to Francine, who then changed course and disappeared into an alleyway.

Greta hailed the taxi driver, a handsome young monkey man who sat behind the wheel eating a cream donut. "Follow that gray car!" she ordered, pointing toward the intersection where Mr. Baker's Oldsmobile was stopped at a signal.

The driver looked incredulously at the three small children who had suddenly arrived at the window of his vehicle. "I'm not running a school bus, little girl," he said petulantly.

"Don't take that tone with me, young man!" Greta retorted.

"These children are with me," came a woman's voice from behind Arthur and Greta.

They turned and were surprised to see an attractive young monkey woman, probably eighteen years old, with shoulder-length brown hair. She wore blue jeans and a red coat, and held D.W.'s unicorn horn in her hand. Their jaws dropped when they realized her true identity.

"Get in," said the taxi driver, waving his hand. The monkey woman climbed into the passenger seat, while Arthur, D.W., and Greta loaded themselves into the back seat and started to fumble with their seat belts.

"Follow that gray Oldsmobile," said the monkey woman. "We must find out where it's going."

"Yes, ma'am," replied the driver with gusto. The enthusiastic tone of his voice indicated that he seldom had the opportunity to transport such a comely female passenger.

"One brilliant idea after another," Arthur remarked as the cab pulled into the busy street. "I don't know how Francine does it."

As the taxi followed Mr. Baker's car to the edge of town, the driver engaged in a friendly conversation with the monkey woman.

"Any day now, the public will discover my novels, and then I won't have to drive this crate around anymore," said the young man.

"You like to write?" said the monkey woman wistfully. "That's so romantic."

"What about you?"

"Oh, I like to write too. Last year I published my own newspaper. But my favorite thing is sports. I want to be a professional athlete when I grow up." She looked at the driver and sighed ecstatically. "Or maybe I'll just get married and have kids."

"He's too old for you, Francine," called Arthur from the back seat.

"Francine," mused the driver. "What a lovely name. I had a dog named Francine once. My name's Mitch. Mitch Branca."

"Francine loves Mitch," said D.W. mockingly.

The young woman turned her head and glowered at her. "No more wisecracks out of you, or you're grounded."

The taxi continued to pursue the gray Oldsmobile for several miles along the highway, at which point it pulled off into a residential area. A few minutes later Mr. Baker stopped his car in front of a white house with red trim.

"Don't turn," Greta told the driver. "We don't want him to suspect anything. Just stop at the next intersection."

The driver complied, and Arthur, D.W., Greta, and the grownup Francine scrambled out of the cab. "We won't be long," said Greta.

Inside of the house that Mr. Baker had entered, the teacher was displaying Greta's horn to a friend of his who happened to be a physicist at a nearby laboratory.

"No, I can't say I've ever seen anything like it," said the physicist, his expression one of fascination. "I'll put it under the scope and check it out tomorrow."

As he curiously rotated the horn in his hands, the doorbell rang. He went to answer it, and found Greta, D.W., and the adult Francine standing on the doorstep and smiling.

Annoyed, Mr. Baker slapped his forehead. "Oh, man..."

Greta held up D.W.'s horn so that the physicist could see it. "We're selling phosphorescent hood ornaments to raise money for Girl Scouts," she told him, "but I see you've already bought one."

The suddenly angry scientist turned to Mr. Baker, wrapped his hands firmly around the ends of Greta's horn, and snapped it in half. "You never give up trying to make a fool of me, do you, Ralph?" he said as he dropped the two halves to the floor.

The hippo man began to stammer, horrified at the waste of a perfectly good magic horn. Grownup Francine and the two girls fled from the doorstep and down the sidewalk toward the waiting taxi. At one point Greta looked back and saw Mr. Baker in front of the scientist's house, shaking his fist and bellowing, "Stupid meddling kids!"

----

The taxi came to a stop in front of Arthur's house. Greta handed the driver a bill, and she, Arthur, and D.W. unlatched their seat belts and began to exit the taxi. As grownup Francine opened the passenger side door, the taxi driver placed a hand on her shoulder. "I hope I'll see you again," he said longingly.

She gave him a light kiss on the cheek. "You will, Mitch. In about nine years."

As the taxi departed, grownup Francine gazed after it, her eyes glowing with affection. "Oh...he's so cute..."

Greta tapped her on the hip and held out D.W.'s unicorn horn. "Snap out of it, Juliet. You can't go into Arthur's house looking like that."

Francine shook her head and broke free from her trance. "Oh, right." She laid her hand over the horn. "I wish I was my old self again."

In an instant, the grownup Francine vanished and was replaced by the nine-year-old Francine that the others knew and loved. Her first act was to yank the horn from Greta's hand, grip it at both ends, and break it over her knee. She then tossed the two halves into a nearby bush.

"I've decided I don't want to be a boy after all," she announced, grinning. Arthur put his hand over his mouth and snickered.

Greta sank to her knees and embraced D.W. lovingly. "Why are you hugging me?" the little aardvark girl asked.

"Because I'll never see you again," Greta answered sadly. "I'm going away."

D.W. threw her arms around Greta's neck and began to cry. "I'll miss you, Greta. I always wanted to have a real unicorn for a friend. Will you send postcards, like Buster does?"

"No postcards, I'm afraid," Greta replied. "But you can always go to Fern's and chat with me online."

"So this is goodbye?" asked Arthur. "You're leaving forever?"

Greta rose to her feet and looked at Arthur and Francine with a hint of anger in her face. "You betrayed me to Mr. Baker. Even if I could forgive you for that, it's unlikely that the Council will ever let me visit the human world again after everything that happened. At least, not while any of you are still alive. So, yes, this is goodbye."

"Goodbye, Greta." D.W. waved while tears rolled down her cheeks.

Without another word, Greta turned and began to walk along the street away from her friends.

"Think we'll ever see her again?" Francine asked Arthur.

"I hope not," Arthur answered. "I've seen enough unicorns to last me a lifetime. A two-thousand-year lifetime."

----

The next day, Francine and Beat were playing checkers at the Frensky apartment, and as usual, Francine was losing badly.

"So she turned back into an aardvark girl just like that...zap," Beat commented as she captured three of Francine's black checkers at once. "I've never seen anything like it. And I'm from England."

"The doctors still don't know what caused it," said Francine. "They say things like that sometimes happen to kids when they reach puberty, but they never happen to five-year-olds."

"I wonder what will happen to us when we reach puberty," Beat mused.

"I don't know," said Francine, smiling, "but to be honest, I'm looking forward to it."

The phone rang, and Catherine answered it. "Hey, Frankie, it's for you. Some guy named Mitch."

Francine groaned.

THE END