A/N: Someone asked me to write about the famous switch of secret keepers, and this is what I came up with.

The war was quickly intensifying, and James and Lily were informed that they needed to go into hiding with Harry. It was slowly turning into morning, but Sirius, Lily, and James were sitting at the kitchen table drinking tea.

"We need a secret keeper." James finally spoke up. "Sirius, you're my best mate and like a brother to me. I trust you more than anyone else."

Until recent events, Sirius would have accepted without even considering it. But more and more members of the Order of the Phoenix were dying off. There had to be a spy. Sirius had been working his brain trying to figure out who it was.

"Let me think about it, Prongs." He finished his tea and stood up. "I'll talk to Moony and let you know as soon as I can."

Lily and James nodded. Sirius left soon after, apparating back to Remus and Sirius's flat.

Remus was not home. Remus hadn't been home for a week. Sirius was worried sick, and tried to prepare himself for the worst, in case news came that Remus had been killed. He walked into their bedroom and flicked on the light. He tried to sleep, but found himself worrying too much.

Remus finally walked in the door and Sirius felt relief wash over him. But he looked at Moony and saw things weren't quite right. Remus looked extremely tired and worn out. His clothes were wearing out more and he had bags under his eyes. He mumbled a hello and got into bed without much else having been said.

The distance between them had been growing for months. It was palpable, and Sirius hated every moment of it. He wanted this war to end.

He thought of telling Remus about him being secret keeper, but for some reason didn't. He didn't like keeping secrets, but James was his best friend, and Harry was his god son. People were dying.

"You aren't going to tell me where you've been all this time? I've been worrying about you." Sirius grumbled.

"I can't say. Leave it alone, Sirius."

"Why not?"

"Because it's a secret for Dumbledore. Go to sleep, Sirius."

"You never call me Padfoot anymore."

"Sirius," Remus sighed, "Padfoot, I'm tired. I've been off for a week and I've hardly slept and I just want to go to sleep. Can we please talk about this later?"

"Fine, whatever," Sirius shrugged. "I'm going to see Prongs. I'll be back later."

"Weren't you just there?" Remus rolled over onto his side, facing away from Sirius, trying to get comfortable.

"How did you know I was just there if you were gone all week?"

"It was a lucky guess, Sirius." Remus sounded annoyed. "You're always there."

"I'll be back later." Sirius left without waiting for Remus's reply.

He knocked on the door and James answered.

Sirius walked in without waiting to be invited in. "We need to talk." He couldn't say how he knew it. But he knew that Remus was the spy. He had this nagging suspicion that instead of doing things for the Order, Sirius had been doing things for the Other Side. He was a traitor.

"Should I wake Lily?" Sirius nodded as James ran upstairs.

They sat in the living room. "It's too obvious it will be me." Lily nodded. "But we should tell everyone it is. There's a spy in the order. I can't say who it is, I don't know. We'll tell everyone it's me. Voldemort will come looking for me. But it should be Peter, because that's not what people would expect."

James nodded. "I'll tell Peter."

"Is it okay if I sleep on the couch tonight? Remus and I had a fight." That wasn't quite true. Remus had been annoyed with Sirius, but they hadn't fought. He just couldn't bare to look at Remus anymore. He needed a night away from it.

"No, that's fine, we've got an extra room." James sent Sirius upstairs.

In the morning, James woke up Sirius early. "Get dressed, we're going to go have some fun before I'm locked away. Go get the bike." James didn't tell Lily that he was leaving to go ride an enchanted motor bike with Sirius, but told her that he and Sirius were doing things for the Order.

Sirius and James were flying through London on the bike, going as fast as they could before their stomachs were growling and they decided to get some lunch.

After eating, they were about to get back on the bike when a police officer stopped them, something about parking illegally.

Sirius kicked the bike to life and James flung himself onto the bike, clinging to Sirius for dear life, as the bike sped off down the road. The police officer yelled after them, but they escaped soon after.

"I think we've had enough fun for today, Prongs," Sirius yelled over his shoulder.

"Not nearly enough, Padfoot." James ran his fingers through his hair.

"Let's go start problems somewhere else."