Written for the Big/Lil' Sis Team Competition, where I am Big Sis to DobbyRocksSocks, who wrote the companion piece to this, named 'Keeping His Promise'. You should go check it out.

The prompts I used were: Pairing: Sirius/Remus, Word: believe, Phrase: 'I wish,' Plot Device: an unexpected visitor, Time: just before dawn.

Heeding His Words

Harsh rapping on the door woke Sirius from his slumber much too early. The darkness told him the sun hadn't risen yet; it was probably just before dawn. He wiped sleep from his eyes with the backs of his hands as he pulled himself up to sitting, glancing down at his still sleeping partner when he felt able to keep his eyes open.

The knocking on the door came again, and Sirius sighed before grabbing his dressing gown and heading downstairs to answer it. When he opened the door, two grey eyes he never expected to see again fixed him with what Sirius thought was a guilty expression.

"What are you doing here?" Sirius asked his brother, placing a foot behind the door to stop Regulus from forcing entry.

"I need to talk to you. Please. It's important," Regulus said without the fight in his voice that Sirius presumed he'd hear.

"And here was me happily thinking I'd never see you again," Sirius bit back.

Regulus snorted. "I wish." He looked away from his brother and sighed. "Look, you're in danger. You and your friends. Now, let me in then I can help."

"You expect me to believe that?" Sirius was incredulous. Regulus stared at him adamantly. "Give me your wand."

Regulus didn't even grumble as he reached into his pocket and handed it over. Reluctantly, Sirius allowed him in.

"Be quick," Sirius warned, thinking of Remus still sleeping as he flicked on the light. Regulus allowed himself a moment to look around at his brother's home before he began.

"They've found your safe house. The one with the basement." Sirius frowned, knowing the one Regulus was referencing – it was the one they used on full moons to keep Remus and the general public safe. "They plan on attacking tomorrow-" he paused to correct himself, "tonight. Full moon. They think all four of you will be there, so they'll have a perfect opportunity. Just… find somewhere else. Fast."

As Regulus finished, shuffling sounds were heard on the stairs and a sleepy Remus stepped into the light. "What's going on?" His eyes settled on Regulus. "What's he doing here?"

"I was just leaving," Regulus said, before heading to the door. His hand rested on the doorknob as he turned to Sirius once more. "I've told you what I know, you've got the information; it's up to you what you do with it."

When the door slammed, Sirius sighed and slumped his shoulders, letting go of tension he didn't know he was holding.

"What was that about?" Remus asked as he stepped nearer to his boyfriend.

"I believe my brother was trying to save our lives," Sirius commented.

"Then why are you frowning?"

"I don't know if he was telling the truth."

Remus and Sirius talked for a while, until the sun was streaming through the curtains, and they came to the conclusion that instead of running away from it, like Regulus had suggested, they were Gryffindors – they would fight.

The plan was rather simple, and as soon as the hour was reasonable enough to call others over, they did, and it was discussed at length. By midday, they knew what they had to do.

The autumn night was darkening early, which only worked in the boys' favour. They were hidden around the house, alongside a few other choice Order of the Phoenix members, and they were silent. The three of them – with Peter included whilst Remus was predisposed – didn't need to speak to communicate; all it took was eyebrow movements and tugs of their lips to convey the message that they were bored of waiting.

But they didn't have to wait long. The first cracks of apparition were unmistakeable; the Order members tensed and drew their wands. Voices were heard, though the words were indistinguishable, as they tried the front door. Sirius and James watched, waiting for them to try the door at the back, walking right into their traps.

"It's empty!" a female voice exclaimed. Bellatrix.

Another voice – most probably male – muttered something in harsh tones and footsteps were heard. The group – five of them, so far, passed around the side of the house, meters in front of Sirius – completely unaware of their own folly. It only took a quick analysis of the sizes and shapes of the Death Eater troupe, and a measure of the way they walked, to tell Sirius that Regulus was not among them. He thought that the tall, stately figure with long hair was Lucius, but it was too dark to be sure without getting closer.

As the group reached the target spot, the attackers revealed themselves in flashes of light and noise, spells flying this way and that towards the group. The Death Eaters were well-versed in wand-fights, jumping to defend themselves with a casual ease. The two groups were well-matched, but it was currently a fight of five against eight – there was little chance of the intruders surviving.

Sirius engaged his dear cousin, Bellatrix, in a duel, while James took on the Malfoy heir. Battling Bellatrix as he was, he didn't have time to think about anyone else, or anything else. He thought of nothing but self-preservation, and hoped it would suit him well.

Bellatrix was fierce as ever, highly trained and intent on the kill, but Sirius knew her confidence, and knew it was her weakness. She knew she was going to win; she knew it with every fibre of her being, and she let her defences slip. She let her guard down because what she knew was a lie. As she left herself open on her left side, Sirius slipped a stunning spell in and turned away. He didn't have time to stick around and make sure the fallen really had fallen.

He moved around the side of the house, noticing that Peter was holding his own against who he thought was one of the Lestrange brothers, with Moody to help, and James was gaining on Lucius. Round the back of the house, he saw the Prewett twins struggling against Avery, and was about to join in when it happened. Avery shot a Sectumsempra at Gideon.

Sirius froze. It was the last thing he should do in a battle, he knew that, but he wasn't using the logical side of his brain. Gideon fell slowly, too slowly, like time had slowed down just for that moment. Avery had fired the spell like a bullet, with such meaning that the blood was spurting out of his open wounds with a finality. Fabian was still holding his own in the fight, but his gaze was distracted, turning to his fallen brother, his comrade, his identical counterpart, so frequently that he was missing defences and attacks he could have slipped in. And Avery was grinning.

It was at that moment that the Death Eaters seemed to collectively decide it was too much, they were too outnumbered; something was sure to go wrong. They began to group together, holding defences rather than attacking. Sirius knew they would be gone at a moment's notice. He knew he had to do something. He did the only thing he could think of, the only thing that would make an impression.

"Avada Kedavra!" he called out, aiming his wand at the servants of the dark, hoping it would hit a target, hit someone.

It did. Avery fell. Sirius couldn't help but thank Merlin it was him.

The Death Eaters quickly left, taking Avery's body with them. Out of the corner of his eye, Sirius could see shock written all over James's face. He wasn't thinking of that right now. His gaze shifted to Fabian, to Gideon, and to the harrowing look on both their faces. He knew, even without getting closer, without checking, that only one face still had life in it. They had taken someone precious, someone with life and wit, with humour and a hint of arrogance. A twin. Something precious.

They would pay.