Disclaimer: Y'all know the drill. I do not own any of the characters, settings, or plot devices you recognize, those are JK Rowling's. Please don't sue.

Author's Note: Hullo, all. Been awhile since I wrote fan fic, hasn't it? But this AU has been hounding me for awhile now, so I finally sat down and wrote it. You can think of it as the revised edition of Last of the Line, if you wish. Anyway, FYI this first chapter takes place right after the Knight Bus scene of PoA, so you can orient yourselves appropriately. Cheers! — Loki

Sirius Black shook his head as he watched the Knight Bus pull away, trying to convince himself that startling the boy like that had been doing him a favor. At least this way Harry had thrown out his arm and wand and called the bus. There were dangers anywhere at night, after all, and growing up with Lily's sister he probably didn't know about the wizarding bus system. The Knight Bus would at least keep him out of real trouble.

"That," a voice announced behind him, "was incredibly stupid. He could have gotten seriously hurt."

Sirius whirled around, his hackles rising. A man Sirius was sure hadn't been there moments before was leaning against a nearby tree, watching him. He was perhaps thirty and rather short and slim, with black hair in need of a trim and round glasses. While he was dressed casually in Muggle clothes, there was something familiar about him, and he spoke to Sirius as if he knew the dog was really a man.

"I thought I might find you here, Sirius," the man continued. "Around Harry."

Sirius started to back away slowly. He didn't like where this was going— not if the man knew his name and that he'd gone to Little Whinging because that was where Harry was.

"I swear, if you try to flee like a stray dog I'm going to either stun you or use the full body bind," the man snapped. He drew a wand out of his jacket.

Sirius didn't waste time wondering how a thirteen-inch wand fit in the inside pocket of someone's jacket. He ran.

"Petrificus Totalus."

Sirius dropped to the ground and rolled into the bushes, unable to even move his tail. Footsteps told him the man was coming closer. Sirius was rolled gently out of the bushes and back onto the sidewalk, and the man grabbed his ruff before muttering the counter curse. "God, you're bony," he muttered as Sirius struggled against his grip. "And I'll bet you didn't even eat between Azkaban and Surrey. Now, let's see if I can remember this. . . ."

Blue light flashed. Sirius felt his body lengthening involuntarily and becoming human again. Evidently someone else saw the flash, because a light in a nearby house turned on. The man now had a grip on the collar of Sirius's robes, and when he saw the light he yanked his captive into the bushes. They stopped against the wooden fence of someone else's yard.

After a moment, the light in the window turned off again.

"Good," the man muttered. "They didn't see us."

Sirius tried to yank out of his grip, but the man held on tightly. He may have been small, but he certainly wasn't weak. "Gerroff," Sirius growled, not really expecting any reply.

"If you promise not to run," his captor replied.

Unable to see any way out of it, Sirius nodded.

The other man let go, and Sirius sat up, loosening his collar.

"Remember, I'm the one with a wand. Are you all right?" the man added, leaning against the fence and watching Sirius rub his neck with some concern.

"Fine," he grumbled.

"Good." The man leaned against the wall and shoved his glasses back up on his nose, still regarding Sirius critically. "First things first— did you eat between Azkaban and Surrey?"

"Once."

The man sighed theatrically and started digging through a pocket. "Leave it to my big brother to escape from wizarding prison and come barreling south without so much as stopping for a bite to eat. . . ."

Sirius blinked. While he'd thought the man looked familiar, and in some ways like looking into a mirror, that statement was ridiculous. "You can't be," he said softly.

The man looked up and raised an eyebrow. "I can't be what, pray tell?"

"Regulus," Sirius answered, and shuddered. This man did look remarkably like his brother, down to the quizzical expression and kind of spectacles. "Regulus was killed thirteen years ago on Voldemort's orders because he tried to back out of the Death Eaters."

The man shrugged. "Do I look dead to you?" he asked dryly.

Sirius shook his head. "But you can't be Regulus.. . . ."

"How many little brothers d'you have?" Regulus demanded sensibly, shaking Sirius by the shoulder. "And anyway, my body was never found, was it? I faked my own death. Nott's an idiot. I knew you were no Death Eater because I was one and I would know your voice anywhere. And let's face it, Sirius, only James Potter and Remus Lupin knew you better than I did. Pettigrew didn't even have that honor."

Sirius nodded in reluctant defeat. "All right," he croaked, "for the purposes of this conversation, I'll accept you're my brother. How did you avoid getting killed, then?"

"The same way you got out of Azkaban. Because I'm an Animagus," Regulus answered. He returned to digging through his pockets.

"When'd you become on of those?" Sirius demanded. "And when did you find out I was one?"

"I found out only a couple months after Lupin did, because you were always too reckless and I knew you were up to something. I became one your seventh year, actually. I wanted to keep an eye on you. A few other people, too, but mostly you. I couldn't do it as a human, at least not out of school."

"You made a damn good spy even when we were kids."

Regulus looked up with a grin. "I'll take that as a compliment, actually. Anyway, Nott's an idiot and he thought he'd gotten me. He was never very good at the killing curse anyway, so he preferred to blow people sky high." He handed Sirius something wrapped in tinfoil. "Sandwich? I couldn't remember if it was you or Dad that couldn't stand spam, but I was in a bit of a hurry."

Just now Sirius was hungry enough to eat anything. "Frankly, I can't remember, either," he admitted. "So what is your Animagus form?"

Regulus shrugged. "Three guesses."

Sirius looked up from the sandwich in disgust. "I always hated this game."

"That's because I always won. And with your gang at school, Lupin probably always won, too. But still, how well d'you know me? Three guesses."

Sirius groaned. "A snake?"

Regulus rolled his eyes. "Were you trying to bait me or was that a serious guess?" he demanded.

"A little of both," Sirius answered, shoving the last of the sandwich into his mouth. After he'd swallowed, he added, "Didn't think it'd jab at a Slytherin too much, though."

"Shut up," Regulus suggested. "It's not as if I'm Slytherin himself. And anyway, now you're just being pigheaded. I won't count that one."

Sirius actually thought about another answer. It'd have to be something generally thought of as silent, he decided. "A cat?"

"No."

"An owl?"

"Since when have I been anyone's message boy?" Regulus wanted to know.

Sirius rolled his eyes. "Reggie, it's been thirteen years since I even thought you were alive. Nearly fourteen since we last spoke."

"You have one more guess," Regulus answered with a shrug. "Then I'll tell you."

"I really don't know," Sirius snapped, balling up the tinfoil and chucking it at his little brother. He no longer doubted this was Regulus. Only Regulus could get on his nerves so quickly. Well, James could've when he wanted to, but . . . James was dead. "A moose."

"Now I know you're just being stupid." Regulus grinned slightly. "A fox, actually."

"You?"

"Sirius. . . ." Regulus shook his head. "I haven't quite worked out how I ended up a fox myself, honestly. But anyway, why'd you get out? Other than the dementors, obviously."

Sirius sighed. "Fudge inspected Azkaban a couple of months ago. He gave me his paper. And there on the front page—"

"Pettigrew," Regulus interrupted. "I'd been getting the Daily Prophet under a pseudonym. I saw him, too. Or at least, a rat that looked familiar. The four've you have never been far from my mind, so I couldn't help but wonder. But I thought you'd killed him."

Sirius scowled. "I tried."

Regulus sighed and started toying with his glasses. Sirius knew his brother well enough to know from that alone he was nervous. He had never stopped playing with them the last time the two had seen each other or held a conversation, the day Regulus had told Sirius what he'd been up to in the month since he graduated. "I really should have told you he was one," he whispered.

Sirius stared at him in surprise. "You knew?" he demanded hoarsely.

"Don't look at me like that, Sirius. You had told me you never wanted to see me again, and at seventeen I was just petty and bitter enough to take you at your word. Besides, I'd been in France six months by the time it was the Potters' lives in the balance." Regulus shrugged and shook his head. "I didn't think it would take something like their deaths for you or Lupin or them to figure it out in your own time."

For a few minutes the two of them just sat there, hidden by the bushes and leaning against a wall. "So where've you been for the past thirteen years?" Sirius asked softly, mostly to break the silence.

"Trekking across most of Europe in the guise of either a tourist or a fox," he admitted. "Well, other than the four or five years I spent trying to be a Muggle in France. Never quite mastered the language."

Sirius rolled his eyes. "You never came out of hiding?"

"I'm supposed to be dead, Sirius," Regulus reminded him. "Or have you already forgotten the way you panicked when I said you were my big brother? I could hardly come back out in the open."

Sirius snorted, and silence resumed. After some time Sirius wondered if they were going to spend the night hiding in the bushes, waiting for the other one to say something.

"Why'd you come back to Britain, then?" he asked softly.

"To reconcile with you, I s'pose. Or just to keep you out of trouble," Regulus answered quietly, not looking at Sirius. "You are my brother. I made a stop at London on my way here, just after I crossed the channel. Mum and Dad are dead, which I guess makes you the only family I've got left." His voice dropped even lower, and for a moment the collected man Regulus had become reverted to the frightened five-year-old that used to go running into his brother's room every time he heard thunder. "I never wanted you to hate me, Sirius."

Sirius hesitated. He'd been sixteen the last time he'd done much but shout at Regulus. After a moment, though, he reached over and squeezed his brother's shoulder. "I don't," he whispered. "At least, not anymore."

Regulus nodded. "Are you going to Hogwarts after Pettigrew?" he asked, suddenly the collected adult again.

"Hell yes, I'm going after Peter," Sirius answered. "Are you coming with me, then?"

Regulus smiled slightly. "Hey, someone has to keep you out of trouble."

Sirius chuckled and got to his feet, becoming the black dog as he did so. After a moment he looked back to see that Regulus had also transformed, into a scrappy-looking gray fox. Inwardly, he grinned— his brother had changed a lot, but he certainly didn't think that was a bad thing.

The two canines nodded to each other and Sirius started down the street, Regulus half-running to keep up.