Sirius stood open mouthed at the retreating back of his cousin.

"What- did- what"

"It's alright mate she was bluffing," James patted Sirius on the shoulder and led him towards the Great Hall.

All through dinner Sirius kept shooting nervous glances towards the Slytherin table where Bellatrix was laughing with Malfoy, the boy who had stolen Peter's bag.

"She wouldn't tell him would she?" he kept asking.

"I don't know Sirius, she might," Remus said quietly.

"Shut up Remus of course she won't she was bluffing!" James snarled at him.

"Well what if she wasn't?"

"She was! You don't know what you're talking about!"

"Look all I'm saying is that Sirius should be prepared for what might happen," Remus looked calmly up into James's angry face.

"There's no point getting him worried!" James stood up and looked defiantly into Remus's eyes.

"Mr Potter!" Professor McGonagall walked briskly towards the table. "Calm down or will I have to put you in detention yet again?" James opened his mouth as though to reply, but thought better of it and sat down.

"Thank you. Now Mr Potter and Mr Black you are to do your detentions tonight at eight o clock don't be late."

That night at quarter to eight, James and Sirius climbed out of the portrait hole and made their way to McGonagall's office. Sirius was still angry about Bellatrix, but tried hard not to mention it- it wasn't worth causing another argument. He hated to admit it, but he couldn't lie to himself, Remus was right.

"Ah Mr Black, Mr Potter, in here please," Professor McGonagall opened her door and ushered them inside where they were set the task of writing lines.

Three hours later, they were freed. James seemed to have forgotten the argument he had had with Remus as they strolled along the corridor, chatting happily. They were just passing a large mirror on the fourth floor when Sirius tripped over his cloak.

"Ah!" he mumbled as he tried to detangle himself, "Bloody stupid thing!"

"Shut up Sirius and look at this!" James grabbed his friend's shoulder and pulled him to his feet. The mirror had slid open to reveal a dark tunnel behind it.

"What happened?" Sirius bent down to pick up his wand, which had been thrown out of his bag when he had fallen.

James took out his own wand and looked puzzled for a moment, then he tapped the mirror, which instantly slid closed. He tapped it again and it opened once more.

"You know what this is, don't you!" James was practically jumping up and down with excitement as he hopped inside the passage.

Sirius thought for a moment, then his eyes lit up as he realised. "A secret passage!" he stepped in beside James and they tapped the reverse of the mirror. They were plunged into darkness for a second, but then candles all along one side of the tunnel burst into flame.

"Come on!" James started running down the tunnel, Sirius close at his heels.