A/N: Thanks for the reviews, I was really inspired to do this chapter, it's one that I had been looking forward to writing. I hope you enjoy it!

Declarations of Loyalty

Chapter 5: The Break In

Regulus had insisted on sitting down and making a plan, making a map, talking about every worse-case-scenario that came to mind.

James had dropped off his invisibility cloak for Sirius to use. Regulus had suggested that he go under the cloak and Sirius go to the vault, but Sirius pointed out the major flaw that he had his own separate Gringotts vault since being disowned, and it was nowhere near the Black family vault, or the Lestrange vault.

So Regulus had agreed to be visible. He saw so many problems with this, but he did not protest.

Regulus had also been tricked into agreeing to Imperius the goblin into opening the vault. Sirius explained that he would be playing lookout and therefore would be far too busy to do such a thing. Regulus had protested that he had never actually done an Unforgivable Curse, and Sirius sneered.

After a week of planning, they felt they were as ready as they'd ever be.

Sirius would accompany Regulus as Padfoot until they got into Diagon Alley, then Sirius would find somewhere to transform and throw on the cloak, Regulus would then oh-so-casually stroll into Gringotts and ask to be taken to the Black family vault. From there, he would Imperius the goblin to open the Lestrange vault, he would search it for a Horcrux, and Sirius would watch for anyone coming down their way.

They felt they had discussed every possibility.

"Ready?" Sirius asked Regulus.

"Oh, sure," Regulus muttered sarcastically. "It's not as if we're breaking into a High Security vault in heavily guarded wizarding bank or anything. This will be just fun."

"Lighten up. What's the worst that could happen?"

There were several things that Regulus could list off the top of his head that could go seriously wrong. By the time he opened his mouth to speak; Sirius had transformed into the giant black dog and was pawing at the front door.

Regulus pushed the door opened and followed Sirius' wagging tail out. Sirius bounded down the sidewalk, Regulus hurrying to keep up.

"Si- Padfoot! Stop it!" he called, annoyed. Sirius' doggy-face looked back at him and his tail lowered, his pace slowed down. They got to the Leaky Cauldron and Regulus tapped the appropriate brick as Sirius barked at pub-goers enthusiastically.

Once in Diagon Alley, Regulus followed Sirius to a small, hidden alleyway, where he transformed and put on the cloak.

"You're sure about this Sirius?" Regulus asked anxiously, looking up at the snowy white building.

"Too late to get cold feet now, Regulus," Sirius said, following Regulus towards the building. He went inside, Sirius so close to him he could feel their arms brushing together. He walked up to the front counter.

"I need to go to the Black family vault, please," he said politely to the goblin that had looked up at him. The goblin nodded and gestured for another goblin to take them down.

After a nauseating cart ride, they were deep underground, facing the huge vault that all of the more valuable (and possibly dangerous) Black treasures were hidden in.

"Do it," Sirius hissed in his ear. Regulus took a deep, rattling breath and clutched his wand.

"Are you sure?"

"Yes," Sirius hissed, hoping the goblin couldn't hear him.

Regulus bit his lip, drawing his wand. "Imperio!" he said, pointing at the goblin.

"Tell him to take you to the Lestrange vault," Sirius muttered.

He did and the goblin got back in the cart and they followed. The Lestrange vault was only four vaults down from the Black vault. He made the goblin open the vault for him, and with Sirius stationed outside the vault with the Imperiused goblin, he pulled himself into the vault, looking for anything that could be the Horcrux.

Then he saw it, at the very top of a huge pile of gold and silver, the little gold cup with a badger on it and two wrought handles. He clambered over and grabbed it, amazed again at his dumb luck that nothing had happened.

He jumped out of the vault and closed it, they got back into the cart and finally got back to the surface.

Then something happened that neither Sirius nor Regulus, in all their planning and worst-case scenarios, had expected. Bellatrix and Rodolphus Lestrange strolled into Gringotts. By the time Sirius or Regulus could move again, the pair had spotted Regulus.

Bellatrix narrowed her eyes and quickened her pace, heading straight for the frozen brothers. "Is that my dear cousin Regulus I see there?" she asked no one in particular, drawing her wand. "Oh, dear, I was under the impression you had been killed," she cooed.

"I-I," he started, trying to concoct a lie. "I faked my death."

"Or you didn't, and your friend lied to the Dark Lord," Bellatrix corrected. "Grab him for me, Rodolphus."

All of the goblins had stopped to watch, but they were not ones to involve themselves in the affairs of wizards, so they did nothing to intervene. Rodolphus, who was the size of Regulus and Sirius put together, easily, grabbed Regulus by his arms. He couldn't grab his wand, or anything. Bellatrix pressed the tip of her wand to his temple.

"I could kill you now, and then have your lying, traitor friend killed later," she told him. "So what brings a dead wizard to Gringotts?"

"I just-" he panted. "Had to check the vault," he finished lamely.

"Don't lie to me, cousin!" Bellatrix snapped, her voice rising hysterically. "What are you plotting?" she screeched.

"Nothing, I'm not plotting anything!" Regulus said, struggling against Rodolphus' grip.

"Stupefy!" someone shouted from beside them, the force of the spell took both Regulus and Rodolphus off their feet. Regulus stood up and looked down, Rodolphus was unconscious on the floor and Sirius had pulled off the invisibility cloak, and was pointing his wand at Bellatrix.

"Oh, has big bad Siwius come to help his pwecious widdle bwother?" Bellatrix taunted in a horrible mock-baby voice, her wand pointed at Regulus' heart. "How will poor Sirius feel when I kill his widdle bwother?"

Sirius snarled. "Stay away from my brother, you crazy bitch," he growled.

Regulus drew his wand; Bellatrix only had eyes for Sirius, and didn't notice the subtle movement. But suddenly she turned on him and fired a curse straight at him, he only just got out of the way, the spell barely nicked his arm. He wasn't concerned with that; the cup had rolled out of his robes when he had dived out of the way.

"The cup!" Regulus shouted, scrambling to grab it as Sirius fired a curse at Bellatrix.

"You've been in my vault!" Bellatrix screeched madly, dodging Sirius' spell to go for Regulus again. Regulus got back to his feet and looked around.

"Sirius! Catch it!" he shouted, throwing the cup towards Sirius. At that moment, Bellatrix fired a Killing Curse, Regulus ducked out of the way and it hit the airborne cup, shattering it. A black, blood-like substance bled out of the two halves and there was a tiny scream of pain.

Bellatrix looked at the pieces of the cup, horrified. Sirius and Regulus took this moment of distraction to their advantage.

"Stupefy!" they both cried, both of the spells hit Bellatrix and she fell. Regulus walked over to her and looked down.

"She's just unconscious, let's get out of here," he said, stooping down and grabbing the pieces of the cup. "What? I'm going to show Professor Dumbledore, just to make sure it's completely destroyed."

Sirius threw the invisibility cloak over the two of them and they hurried out of the bank, Apparating as soon as they were outside the doors. They appeared on the balcony of Sirius' flat, breathing heavily.

"That was," Regulus started, throwing the cloak off of him and walking inside. "A disaster."

Sirius shrugged. Regulus threw himself down on the sofa and crossed his arms over his chest.

"Regulus, you're bleeding," Sirius said, wincing at the sight of the torn robes and bloody arm.

"It's fine," Regulus grunted, pulling off his torn robes. "Nothing we can do anyway, it's a curse wound."

"I have some bandages around here somewhere," Sirius muttered.

Regulus stared at the carpet. "They're going to kill Barty, aren't they?" he asked in an unnaturally high voice. "Bella is going to tell them he didn't kill me."

"Maybe he can lie his way out of it," Sirius lied, wincing, digging through the cupboard, looking for some bandages. He found them and walked back to where Regulus was sitting. "Hold out your arm."

"Sirius, I can bandage up my own wound," Regulus protested, sounding very much like a five year old. Sirius gave him a look and pulled his bleeding right arm towards him, looking at it carefully before wrapping the bandages around it and tapping it with his wand.

"Stop being stubborn and let me try to help you out once in a while," Sirius said, standing back up. "It's what I'm here for."

Regulus frowned. "Thanks."

Sirius paced a lot for the remainder of the day; he had a tense grip on his wand at all times, as if he was expecting an attack. After a tense, quiet dinner, he told Regulus to go to bed.

Regulus lay in his bed, unable to sleep. His mind was racing, thoughts of Bellatrix, the Death Eaters, a dead Barty, a dead Sirius. Things that scared him, but somehow during the night he drifted off into sleep.

The next morning he woke up with a huge black dog lying on the floor beside his bedroom door. He got out of bed and sat down beside the huge sleeping dog, scratching him behind the ears, trying to wake him up.

The dog opened a large pale eye at him and stood up slowly, stretching himself out. Regulus stood up, and the dog transformed back into Sirius.

"Why'd you sleep in here?" Regulus asked.

Sirius shrugged, but didn't answer. Regulus thought that Sirius had been more worried about him than he had let on. Regulus rubbed his wounded right arm a little.