I found dozens of such fanfics based on Pride and Prejudice, so decided to give the idea a try in the Labyrinth fandom.
The Agreement
Robert Williams looked at the money they had and sighed:
"It's no use, Irene. We'll have to move out of the house. Even if we sell it, it will only cover half of the bills."
His wife sobbed:
"What do we do? We have two children to feed! And we need at least something just to rent a house."
"If only Linda hadn't died in that airplane crash… She was proud and selfish, but not completely merciless," Robert murmured. His first wife Linda, a Hollywood star, died a year and a half ago. Everything she had passed to her third or fourth husband, who refused to have any connection with the Williams family.
The new financial crisis ruined all of them. Robert's company went bankrupt, Irene was fired because she wasn't a very valuable worker. So the couple with their three-year-old son Toby and Robert's seventeen-year-old daughter Sarah was sitting with no money and a mountain of debts. Sarah, an ethereal imaginative young lady, could do naught to help them but practice creative writing. Unfortunately, her fairytales were never published: the publishers found them too difficult for little kids' minds.
As Robert tried to comfort his desperate wife, Sarah came downstairs, reading her favorite fantasy book. Robert looked at his daughter with a hint of anger:
"Sarah! You're reading children's stories while we are trying to figure out how to support our lives!"
He walked to the girl and glanced at the book.
"A beautiful young girl… the Goblin King… the Castle Beyond the Goblin City… Honestly, Sarah, do you really believe in all this?"
"Yes!" Sarah said firmly. "And it cheers Toby up."
She made herself a cup of hot coffee, drank it and went away again. Irene broke into sobs once more:
"Oh dear, oh dear, how will our children live?!"
Thunderstorm raged outside. Robert grimly shut the windows' curtains. He felt like in a movie of some kind: when a movie's character experiences difficulties, the weather is always like this.
Only Robert couldn't hope for a brave hero to run and shoot every villain (well, the people who sent the bills) with his ever-present pistol.
Suddenly, the windows opened wide and a white barn-owl flew into the hall. As it reached the dumbfounded people, it turned into a fierce-looking but handsome man with messy blond hair, dressed in a dark-scarlet cape.
"Oh, Robert, I think I'm going crazy," Irene groaned, putting her hand to her forehead.
"If you are, I am as well," Robert said. The stranger laughed:
"I assure you, you're not going crazy. Of course, I don't usually come to people without being invited…"
"Who are you?" Robert exclaimed.
"Jareth, the Goblin King. I've come to help you."
"We are going mad, dear," Irene said to her husband. "It's all Sarah's book."
"Partly, it is," the Goblin King chuckled. "But I'm very much real."
He outstretched his hand, and a crystal orb appeared on it. Robert and Irene stared at the orb, shocked.
"If you take it, you will be given your dreams, even the most… prosaic ones. You'll get your jobs back, your son will grow up to be a celebrity, you'll move to New York in a few months… anything," Jareth explained. Robert frowned suspiciously:
"You're helping us for nothing, sir?"
"Naturally, I'm not!" Jareth said triumphantly. "I'm tired of just plain watching and waiting. I want to have your daughter's hand in marriage."
"What?" Robert cried, feeling like a drama character again. "Sarah's hand in marriage?"
"Mr. Williams, you may be certain that your daughter will be happy. Very happy," Jareth's cold fierce face brightened with a genuine feeling. "I've loved her for years, since I first saw her in that park. I come to your world regularly, you see, in an owl's shape. That is how I first saw Sarah. She will be my Queen Consort, she will have everything she needs and more. She will live in a fantasy world – isn't it her greatest wish?"
Irene looked at Robert. Robert looked at Irene. Then he slowly said:
"Your Majesty…"
"Oh, please, not the title!" Jareth laughed. "As my possible future father-in-law…"
"Sir," Robert continued, "we believe you, and it's extremely good of you to offer us help, but you need to talk to Sarah. We don't live in the Middle Ages. We need to know her opinion of all this."
"Fine."
"Sarah!" Robert called. "Come down here!"
In a few minutes, Sarah came running and stopped abruptly when she saw the King.
"You!" she cried breathlessly. "Why did you come again? You can't have Toby!"
"Sarah," Jareth said gently. "I don't want to have Toby. As far as I know, no one has wished him away anymore."
He took her hands in his:
"I've come to offer your family help."
"Help?" Sarah raised an eyebrow. "Since when do you offer anyone help?"
"You don't know me, Sarah," Jareth said. "I've helped many people. And basically it's only this time I want something in exchange. You as my wife, to be exact."
Sarah blinked:
"Y-you were serious two years ago? With the love songs and that offer?"
"Yes," Jareth sighed. The girl swallowed:
"I… I thought it was just a trick of yours… to stop me from finding Toby… I'm so sorry!"
"What is going on here?" Irene interrupted, exhausted and worn out.
"Sarah, just tell me whether you want to marry me – at least for your family's prosperity," Jareth whispered. "Let's discuss our past mistakes later."
Sarah looked around the house, which was virtually empty – everything was sold. She looked at her father and stepmother, who were thin and extremely tired and had dark circles under their eyes. She remembered that herself and Toby looked even worse.
"Yes," she nodded. "I think I may even grow to love you."
