A/N: Set during Poisoned Chalice. MAJOR AU on The Devouring.

Disclaimer: Am I old enough to have a job? No. Figure it out.

Gaius tipped the antidote into Merlin's mouth while Arthur and Gwen watched anxiously. Merlin's breathing started to even out.

"Will he be all right?" asked Gwen nervously.

"As long as we prepared the potion correctly, yes." answered Gaius.

Merlin suddenly stopped breathing. An ominous voice began to echo around the room.

"Henry... I'm back..."

Gaius' eyes widened in horror.

"No..." he whispered. Not again, he thought.

Merlin got up and opened his eyes, staring at Gaius. "Hello again." His voice was cold and calm, and his once blue eyes were an inky black.

Arthur and Gwen were completely silent, staring at the two.

"You..." Gaius uttered.

The boy that used to be Merlin smirked and said, "Do you remember, Henry? What I did to you? To Regina?"

"Don't you dare say her name, demon!"

At last, Arthur spoke. "What are you?"

"He's a Vour. A demonic being of pure terror. Luckily, I know how to stop one."

Gaius grabbed a bucket of icy water and threw it at the Vour.

Said Vour grunted and doubled over in pain. He looked up at Gaius. His eyes were blue and tortured.

"Go! Get out of here!" he groaned.

Gaius gaped. "Merlin?"

"Hurry!" he pleaded.

They rushed out of the physician's chambers. Gaius turned and saw Merlin sprawled on the ground, unconscious.

He didn't look back again.

The three of them went to Gwen's house.

"Okay, Gaius," said Arthur after he had caught his breath, "tell us the truth. Who are you?"

Next chapter, we'll find out who Gaius really is! Oh, the tension!