Triwizard Tournament

The Great Hall of Hogwarts was dimly lit, illuminated only by the bluish glow of the Goblet of Fire. At the Ravenclaw table, fifth-year Adeline Froze nervously fiddled with the hem of her robes. She wasn't seventeen yet, but a strange premonition had been nagging at her all evening.
Albus Dumbledore stepped forward. The fire in the Goblet suddenly turned a brilliant scarlet. There was a hissing pop, and the first charred parchment flew into the air.
"The Champion of Durmstrang," Dumbledore announced, "Viktor Krum!"
The hall erupted in applause. Soon, the Goblet spat out a second note: Fleur Delacour had become Beauxbatons champion. The third parchment revealed the leader of Hogwarts—Cedric Diggory. The hall literally shook with applause, and Dumbledore began his final speech, when suddenly the Goblet's flames began to screech madly again and ejected a fourth piece of parchment.
Dumbledore caught it, frowning. The hall fell silent.

• Harry Potter.
  As a shocked Harry, pushed toward the exit by Hermione, the Goblet of Fire rose madly for the fifth time, producing a blinding shower of sparks. The note landed smoothly in the stunned headmaster's hand. A deathly silence fell.
  "Adeline Froze," Dumbledore's voice echoed.
  Adelina's heart sank. Hundreds of students' gazes turned to the Ravenclaw. Professor McGonagall nodded sternly, urging the stunned girl on. Stumbling, Adelina followed Potter to the champions' dorm.
  There, among the ancient tapestries, Cedric, Fleur, and Krum stared in bewilderment at the teenagers who had entered. A second later, the door burst open with a bang. Dumbledore burst into the room, followed by McGonagall, Snape, Karkaroff, Madame Maxime, and Barty Crouch Sr.
  "Harry! Adeline!" Dumbledore rushed towards them. "Did you put your names in the Goblet?"
  "No, sir!" they answered in unison.
  "Did you ask someone more senior to do this?" the director asked.
  "No!" Adelina exclaimed, barely containing her trembling.
  "This is outrageous!" Madame Maxime thundered. "Hogwarts now has three champions! This is cheating!"
  "My castle didn't rig the results!" McGonagall snapped. "Something dangerous happened."
  Snape hissed from the corner: "Potter and the Froze girl have clearly found a way to get around the age limit..."
  The argument escalated with fury until Barty Crouch Sr. spoke. His face remained pale and inscrutable.
  "The rules are unbreakable," he said dryly. "The Goblet of Fire formed a magical contract. From that moment on, both Harry Potter and Adeline Froze are obligated to participate in the Tournament."
  A heavy, ominous silence fell over the room. Adeline exchanged glances with Harry: both understood they had been drawn into a deadly game.

......