Amy did not know much about barns but she was sure this barn was not your usual kind of barn. For one, it seemed far too big for a village this small. And for another, it looked very new and the material seemed to be mimicking wood rather than actually being wood. She had an uneasy feeling as they approached the entrance.

The Doctor strode right up to the doors. "Not locked this time, Pond. Look, it's one of those doors that I can push open with both hands and make a dramatic entrance. I've always wanted to do that."

He put both palms flat on the two huge barn doors and pushed both open at the same time. They opened smoothly. "Alright then. Let's have you."

Merlin's torch lit up the interior of the huge barn as they walked in. There were some tables and chairs in there and a gateway set against the far wall. Framed within its arches was a large crack.

"Huge crack like that, it's amazing the place is still standing," Merlin commented. He walked forward and reached out to touch it but the Doctor nudged his hand away.

"It's not a crack in the wall. It's a crack in the fabric of space and time," he said. "Knock down this wall and the crack would probably still be there, just hanging in mid air over the field." He aimed his sonic screwdriver at the crack, analysing it. "This must be how the Slitheen crossed over to Camelot."

"That's very true, human," a voice behind them said. The three of them quickly turned round and saw two Slitheen, in their true forms, standing in the open doorway, blocking their only escape route. They carried huge weapons in their giant hands. These definitely did not look like the harmless memory wipers they were using in the afternoon. The two creatures advanced, pushing them into a corner.

"Well, that's very opportunistic of the Slitheen," the Doctor said. "And I don't think we've had the pleasure."

"Oh yes, where are my manners?" one of the creatures said. "I am Korst Fex Fotch Sharlaveer-Bar Slitheen. This is my associate, Dram Gogg Thek Lutiron-Day Slitheen."

"I'm the Doctor. This is Amy, and that's Merlin," the Doctor said quickly. Amy gave a small nervous wave.

"It's a pleasure to meet you," Korst Fex Fotch said. "Now, goodbye." He levelled his weapon.

The Doctor stepped forward, waving his hands out. "Wait, wait! Before you kill us, what's this all for? What are you doing in Camelot? Come on, you're gonna kill us anyway, what would it hurt to tell us?"

"He does have a point," Dram Gogg Thek noted, turning to his companion.

"I disagree," Korst Fex Fotch answered. "A little knowledge can be a dangerous thing. The fewer people know, the better it is. That's just business. No mess, no fuss."

Without any further ado, he fired his weapon. At the same time, Amy screamed, the Doctor brandished his sonic screwdriver and Merlin shouted out something. There was a flash of blinding light that burned even as everyone shielded their eyes.