The Potions Master and the Ravenclaw

Barty Crouch Jr

Author's Note: a little more paraphrasing/ quoting from GoF here. Credit to J. K. Rowling.

....

Finally the third task of the Tri-Wizard Tournament was upon them.

Hagrid had grown a 20-foot hedge maze over the quidditch pitch and the champions had been informed that the object of the Task was to navigate the labyrinth (which would be seeded with various spells and creatures), and reach the Triwizard Cup, located in the center of the maze. If the champions wanted help or wished to withdraw from the competition, they were to send up red sparks from their wands and help would be dispatched. Hagrid, Professor Moody, Professor McGonagall and Professor Flitwick were to patrol the outside of the maze during the task, ready to help if any of them got into difficulty and wished to be rescued. The first Champion to touch the Cup would be the outright winner.

Harry Potter and Cedric Diggory were to enter first, followed by Viktor Krum and then Fleur Delacour.

Ludo Bagman blew his whistle, and Cedric and Harry disappeared into the maze. Krum and Fleur followed.

And now there was nothing to do but wait.

Madeline and Madame Pomfrey stood by the entrance, hoping their services would not be needed. Snape was nearby, talking with Dumbledore.

After some time had passed, Fleur Delacour was carried back to the entrance of the maze by Hagrid. She had been stunned. Madeline and Madame Pomfrey revived her and examined her. Fortunately she was otherwise unharmed and Madeline spoke calmly to her in French until her family came down from the stands to be with her.

Soon after, McGonagall brought Viktor Krum to them. Having seen red sparks sent up from the maze, she had entered the labyrinth and rescued him.

"He's been cursed. The imperius curse," McGonagall said, concerned. "That may explain Miss Delacour's condition as well. Krum may have stunned her. But who cast the curse on him? And why?"

Madeline felt a sick sense of deep dread. "Something isn't right, Professor. This seems an ominous sign. This feels...evil. Dark. Not part of the game." She looked down at Krum.

"Yes. I'm afraid your right." McGonagall looked grim.

"I'm going to get the Headmaster."

"Yes, quickly, Madeline," said Madam Pomfrey. "I'll take care of Mr. Krum."

Madeline ran to find him, forcing herself to stay calm.

Madeline found Dumbledore and Snape together and she quickly relayed what had happened. The two men followed her back to where Krum had been released from the imperious curse by Madam Pomfrey. Karkaroff was standing over the boy, speaking sharply to him in Bulgarian.

Madeline looked at Snape. "Severus, what can this mean?"

"I... I don't know. Someone has cursed Krum. To what end, I do not yet understand." His brow was deeply furrowed as he tried to process what was happening.

Dumbledore looked deep in thought.

"What about Potter, Dumbledore? And Diggory, of course. Should we end this before they are harmed, as well?" Snape asked calmly.

"It is possible we are too late, Severus."

"Oh, Albus!" McGonagall exclaimed.

Just then Snape grabbed his left forearm and his face went white.

"Severus!" Madeline cried.

His face was like a stone. Like a death mask. His eyes clenched shut, right hand still clasping his arm.