Harry didn't know why he tried it. The only thing he could figure was that he wasn't entirely in his right mind at the time. He had been racing around a cemetary dodging Death Eaters and Lord Voldemort less than an hour after running through the maze from hell. It was probably thinking about the maze that reminded him of the movie he had heard many times several years before while sitting in the cupboard under the stairs. The one Aunt Petunia turned off with a loud shriek half way through when she finally noticed what Dudley was watching, and didn't hear again.
Next thing he knew he was shouting "Goblin King, Goblin King, I want you to come and take this Voldemort away from me!" while avoiding several nasty hexes. After all he was dead anyway, any dumb thing he tried wouldn't hurt.
Several Death Eaters looked at each other and decided that it would be best to back off. It had been several generations since a wizarding child had been dumb enough to call for the Goblin king, and it would be best to be well back so they didn't end up in the middle of it.
Noting the reduction in pursuers, Harry said it again.
The Death Eaters who decided to back off Disapparated. They weren't being paid to hang around for this. If Voldemort wanted to kill some loony kid who was dumb enough to try summoning King Jareth, he could do it himself. They had heard the old stories and weren't going to have any truck with what was coming next.
Emboldened by the sight of several of his pursuers leaving, Harry turned to Voldemort and said. "I wish the goblins would come and take you away right now."
"Your wish is my command." Said a tall blonde in really tight pants who had suddenly appeared right behind Harry. "If you want him back, you'll have to go through the Labyrinth and reach my castle in thirteen hours."
"Huh?" Said Harry who wondered what kind of person would go around in pants like those and if the bulge was real or the result of something having been stuffed down the front of his trousers.
"I said, if you want him back, you'll have to go through the Labyrinth." Jareth said wondering why everyone kept ignoring him and staring at his crotch, the boy in front of him being no exception.
"Oh, fuck that. I don't want him back, you can keep him." Harry said finally looking up at Jareth's eyes.
"Would anyone else like to get him back?" Jareth said as he looked pointedly at the Death Eaters who had remained behind to watch the spectacle.
Each one of them muttered apologies about urgent appointments that they needed to keep as they vanished one after the other.
"Well It looks like I won't have to waste my time waiting the full thirteen hours then." Jareth said as he banished Voldemort back to his castle.
A week after the cemetary incident, Severus Snape stood in line at Gringotts grinning as he watched as an ill-tempered goblin bearing a nametag with the name Voldemort on it angrily slammed the recently exchanged muggle money down on the counter in front of the person ahead of him. He could torment his former master all he wanted and there wasn't a damn thing he could do about it.
"Hello, I'd like my Galleons converted to Pounds, then the Pounds converted to American Dollars, then the Dollars converted to Yen, then the Yen to Rubles, the Rubles converted to Rupees, then the Rupees converted to Canadian Dollars, then the Canadian Dollars converted to Pesos, then the Pesos converted to Francs, then the Francs converted to Lira, the Lira converted to Chinese currency, then the Chines currency converted back to American dollars, then the Dollars converted to Pounds." Snape said smirking evilly when it was his turn.
Harry happily opened his birthday presents. Life had been going pretty good for him this past month. Wormtail had been captured and turned over to the Ministry by several former Death Eaters who feared what would happen if Harry summoned the Goblin King again, since he apparently got off scott-free last time. Wormtail had been tried and convicted of all of his crimes including the death of Cedric Diggory. Sirius Black had been freed and given custody of Harry. And Harry had discovered that he had family on his mother's side other than the Dursleys.
A Barn Owl with a package tied to its leg landed right next to the cake. Harry took the package.
"Hello Great-Grandpa Jareth. How's Voldemort been working out?" Harry said by way of greeting when the Owl had transformed into the Goblin King and taken a seat at the crowded table ignoring the cowering wizards and witches that surrounded him.