A/N: Thank you for all the reviews! I understand the concerns about Harry's characterization. I wrote him the way I did because I picture him as even more emotionally unstable after Sirius's death. He'd be overwhelmed about being transported into this world, I think. Add in having to rely on Snape to get him back home, Pansy not to tell anyone about him being from another world, and everyone else not to find out the secret, and he knows he's walking a tightrope.

However, that's about to change. This chapter should answer a lot of questions, for everyone.

The Best of All Possible Worlds

Chapter Twelve: Trelawney and Truth

"Tea?"

"No, thank you," said Harry, as politely as he could. They were in the tower, Trelawney having dragged Harry there the moment he agreed to listen to her, and it was the only place he had found so far where he ceased to notice his own stink. The smell of incense and drifting perfume and something soft and bubbling was everywhere. Harry feared what the tea would taste like.

"I will have some," Trelawney muttered, and disappeared behind a shimmering, veil-like curtain to emerge a moment later with a steaming cup. She looked less misty than she had, eyes clear. Harry was glad of that. He thought it was about time he started getting some answers, and he didn't want Trelawney drifting off into a vision in the middle of the conversation.

"I want to know what you meant," he said at once. "You said that you had a vision of me."

"Yes," said Trelawney, and sipped her tea. Harry felt a small surge of self-congratulations when she put it down almost at once, but it faded when she said, "It always tastes awful, but it keeps away the Sight for a time." She fixed him with a piercing gaze. "More than sixteen years ago, now. And the time has passed the same in our world as in your own, I see." She smiled sadly. "That I should be facing the person I saw in my vision… it has never happened to me before. I experience visions most often of people I already know."

Harry kept from growling with an effort. "But I don't understand how you can have had a vision of me if you're from this world," he said. "Or how you got here if you were born in mine."

Trelawney nodded. "It really will be easier from the beginning. I'll start there."

That would be the most sensible thing to do, Harry thought sarcastically, and then sighed. This is Trelawney. Sense probably takes her a lot of effort.

But the woman who started speaking to him now looked at least as different from the Divination teacher he knew as the other Snape had from Harry's Snape while he was smiling. "Severus and I were both born in your world. I had visions from my childhood on, but I kept many of them concealed, first out of fear and then—well, out of fear. There were so many horrible things I couldn't prevent. My parents never understood that half the nightmares I cried over were real." Her voice dripped with self-pity.

"But the prophecy of me?" Harry asked indignantly.

His tone seemed to snap Trelawney out of it. "Of course. I eventually got training as a seer, and that was when I learned of other worlds that were versions of our own. At the time, I didn't think much of it. It took a complicated potion to cross between them, for one thing, and I had nowhere near the level of potions skill needed to brew it.

"Eventually I applied for the position of Divination professor at Hogwarts." Bitterness slipped into her voice for a moment. "The Sight was enough to keep me from holding a normal job anywhere else.

"On the night that Dumbledore interviewed me, I spoke a prophecy of you." Trelawney looked him in the eye. "But I had a vision as well. I saw your scar."

"That was how you knew me," said Harry, though he didn't feel satisfied. It doesn't explain why she's so afraid of me.

"Yes. And I saw many other things. It was the longest and most complicated glimpse of the future the Sight ever gave me." She shut her eyes. "I saw Voldemort rise, and how many people had to die to stop him. I saw the destruction spread across wizarding Britain and spill into the Muggle world. I didn't see an end to it before I snapped out of the vision, and found I had spoken a prophecy that only hinted at what was to come.

"I was terrified. Incoherent with horror. I fled Dumbledore, even though I knew I had gotten the Divination job, and sought out Severus."

"I thought he was a Death Eater then," Harry interrupted.

Trelawney shivered. "I have not heard that name in so long," she said. "Yes. He was. But I had encountered him during my training, when he and I had crossed paths in our research. I knew his heart lay more with Potions than with the Death Eaters' version of pureblood superiority. And even then, he had begun to look for an escape. Yet what escape was there, when he had taken the Dark Mark on his arm of his own free will?"

Harry interrupted again. His head had started to ache, and he was inclined to think it was from confusion, even though it could be from the incense. "He could have just gone to Dumbledore."

"Is that what the one in your world did?" Trelawney asked, astonishment overspreading her features.

"Yes—wait a minute, I thought this Snape I met here was the one in my own world." Harry rubbed his scar. It's not as bad as the pain Voldemort causes, but it's close, he thought resentfully.

"Of course, he wouldn't have resented Dumbledore as Severus did," Trelawney murmured, and then raised her hand when Harry opened his mouth to interrupt. "Just a moment. Hearing news from a world I have not seen in sixteen years takes a moment to absorb." She closed her eyes again and sighed, then opened them. "Yes, you do deserve to know what happened."

Harry nodded firmly. He could feel his fear and hesitance melting. Trelawney knew he was from another world already, so he didn't have to worry about revealing the secret to her. And he didn't think she would tell anyone. That made things incredibly different from the way that Pansy and Snape acted around him, and the way he had to act around them.

"Snape agreed to brew the potion that could take me to another world, one where Voldemort didn't exist and we could live happy, normal lives. His price was that he be allowed to come along." Trelawney shrugged slightly. "I didn't know what would happen then, so of course I said yes."

"What happened?" Harry asked insistently, wishing that she would tell the story faster.

For the first time, Trelawney looked at him sharply. "I'll get to that," she said. "The potion works by literally tearing open the gate between the worlds. It takes a lot of magical power to do that, and it's released as—"

"A storm," said Harry, his mind flashing back to the odd and sudden rising of the storm outside Hogwarts. He wondered if his world's Snape, or this world's Snape, or whoever the man he had known for five years really was, had been brewing the potion again.

"Very good," said Trelawney. "Yes. It would have caused just one storm in the hands of a completely skilled potions master, perhaps, but Severus admitted that he was in haste and didn't prepare the potion as carefully as he could have. Since then, there have been a few other storms." She gave Harry an unhappy smile. "But this is the first time someone else came through. I don't know why I didn't foresee this."

She contemplated her hands in silence for a time, while Harry went through the hexes he knew and wondered if there was one that would make her talk faster. Trelawney looked up at last. "When the time came, we walked outside and let the lightning strike us. We woke up here.

"We were overjoyed—until we realized that we had counterparts in this world. They had the lives we wanted, lives of peace, with no Dark Lord tainting them." Trelawney clenched her hands, and a faint tremble entered her voice. "I cannot forgive myself for what we did then, but the guilt becomes easier to live with when there are years between storms.

"The potion allows for two passages back and forth, one for each distinct persona."

"Persona?" Harry was concentrating fiercely now. He didn't want to miss a single nuance of this.

"The people who live in each world. There is the persona of Sybil Trelawney, for example, and the persona of Severus Snape. The persona of Harry Potter." She gave him a weak smile. "So we could have gone back to our own world, but that would have been it. We would not have been able to come to this world ever again "

She bowed her head. "We didn't want to go back. We—we came to Hogwarts, where this world's Sybil Trelawney, a poor seer, had just been offered the position of Divination professor out of pity, and this world's Severus Snape had just become the youngest Potions professor in history.

"We kidnapped them, drugged them with some concoction that Severus made, and waited until the next storm, a few days later. Then we pushed them through into the world we left." Trelawney's voice was now just barely above a whisper. "And we took their places."

Harry was clenching his hands so hard that he could feel his fingernails cutting into his palms. "That was a cowardly thing to do," he said, in a voice that he didn't even recognize as his own. Then his anger faded for just a moment as he recalled things that made that story not make sense. "But I know that the Snape in my world was a Death Eater. Why would he become one, if he didn't believe in that kind of thing here?"

"There are so many limits to each persona," Trelawney said, so softly that Harry could hardly hear her. She was sitting with her head bowed above her lap now, which didn't help. "The order of nature tries to reassert itself as soon as possible. That's why only two passages for each persona, for example. The gates are sealed against us. We can't go back, and the Snape and Trelawney we pushed through into your world—our world—can't return either." She brought her head up with a sharp gasp. "Another thing nature does is reorder the physical appearances of the personas if they exchange worlds as we did, particularly magical markings. The moment the lightning bolt struck the Snape we pushed through, the Dark Mark vanished from Severus's arm. We theorized that it probably appeared on the other one's arm, but we had no way of checking, of course."

Harry felt as if he had been punched in the stomach. He tried to imagine a Snape who had grown up without Voldemort opening his eyes and seeing a snake and skull branded on his arm. He tried to imagine the pain of the first calling, and what he would have had to do if he wanted to survive.

For the first time since meeting the man, Harry thought he might have a reason for the chip he carried on his shoulder.

He looked up to find Trelawney watching him as though waiting for something. "What?" he asked.

"We cannot pass back through the gate," said Trelawney carefully. "But you have come through only once, which means one more passage for your persona. The next storm will show up in a few days. It always does. If you push the Harry Potter who lives here through, then he would remain trapped in the other world. You could stay here. Your scar would vanish, I am sure, and appear on his forehead. You would come to look like him." She took a deep breath. "You could stay here, and live with his friends and family, and have no one notice anything different."

Harry stared at her, a rush of emotions traveling through him. Fear, anger, horror…

And longing, a bit of it. Maybe it was because he had indulged his emotions about Sirius so much over the summer, but Harry couldn't deny that the thought of having parents, and a godfather, and no Voldemort to fight, tempted him. He wouldn't even have to give up his friends.

"Why do you want me to do that?" he asked. "I thought you regretted pushing them through the gate." His voice was sharp, and Trelawney flinched and looked away from him.

"I do," she said. "But that was an action of mindless terror. You would not believe how strongly fear rode me, or I would never have suggested what I did to Severus. I think that you should do this because you have suffered. I saw it. I told you." She looked back at him, and tears stood in her eyes. "And if you go back, worse is to come. Oh my child… so many deaths. So many." She was whispering again by the end of it. "Price after price after price, and years of war. I did not even see how my prophecy came true, if you succeeded in stopping the Dark Lord, or survived."

Harry controlled the temptation to ask who else would die. He didn't want to know. He didn't. The grief over Sirius was bad enough.

He tried to make his voice calm and reasonable, though it was hard after that. "But if I push—him through, then he'll face it."

Trelawney nodded, her face unreadable now. "But he has had sixteen years of a normal life, and you have had none."

And Harry felt as though the punch had been in his brain this time, instead of his stomach.

Why shouldn't the other Harry be a prankster and a prat and not know what to do when a copy of himself showed up? He hadn't had to face Voldemort. He'd never been kept in a cupboard. He had parents. He'd known Sirius all his life. No one had ever accused him of being the Heir of Slytherin. The Sorting Hat had probably put him straight into Gryffindor, without a qualm, without a second thought.

If Harry shoved him through the gate, he would die facing Voldemort. Harry was certain of it. And if the prophecy was right, then the wizarding world and all the people Harry knew might die with him.

Harry swallowed stickily. There was a chance it wouldn't work out that way, of course. Maybe the scar would give the other Harry the power to be Voldemort's equal, and he could save everyone then. Harry could live in blissful ignorance, since the dreams would go with the scar, and he wouldn't know what was happening at home.

But he wasn't going to take the chance.

He opened his eyes, and saw Trelawney holding her wand in her lap, casually. And, gazing at her, Harry was quite sure what she would do if he told her what he had just realized. Maybe that was the Slytherin part of him talking. Harry didn't know, and he didn't care. He was just grateful for it.

"I'll consider it," he said, and tried to look shocked. There was probably no trouble with that, he thought wryly. "It's a lot to think about, after all. I never even suspected that something like this was the truth."

Trelawney relaxed, and took her hand off her wand casually, stretching. Harry hoped he did hide the contempt, but looked down in case he didn't. "You have a few days to think about it," she said. "The next storm will show up within the next two weeks, but it's never been earlier than a week."

Harry's stomach tightened with anxiety. Damn it. Before I go home I somehow have to destroy the Star of Morning.

Not to mention all the other things he had to do.

He smiled, hoping Trelawney would understand why it might look strained. "Thanks, Professor. I'll remember that." He stood up. "And thanks for telling me. Snape wouldn't."

Trelawney gave a small laugh. "I deal with it by feeling guilt. Severus deals with it by refusing to admit it happened." She hesitated. "I am glad that your Snape went to Dumbledore," she said quietly. "It wasn't an option for Severus. He hated the Headmaster too much because he didn't expel Sirius Black for trying to kill him when they were students."

"That didn't happen here?" Harry asked.

"No. I had the feeling that something else did, because your father—that is to say, the James Potter of this world, hated Severus enough on sight. But not something that severe, given that the Snape born here had taken the Potions job." Trelawney hesitated, then smiled encouragingly. "You might think it would be difficult, getting used to a whole new set of relationships with people. But it was harder for Severus than me. He had to work with the Headmaster, and pretend that he didn't hate Potter and Black as much as he did. You're young. You should fit in fairly well. And it really is amazing, how consistent most of the friendships and loves and hatreds are from world to world."

Harry smiled again, wanting to get away from her. Hexing her wouldn't do any good, he told himself firmly. It couldn't give his world's Snape and Trelawney the ability to go back home.

"I thought people would notice a difference," he said casually. "You're a good seer, and the Trelawney you sent through the gate is anything but. She did make one accurate prophecy, and a lot of people think she made the one about me defeating the Dark Lord, but that's still only two."

Trelawney spread her hands. "Dumbledore was a kind man, no matter what the world. I had less worries for my counterpart than for Severus's. Albus would have taken her in, and the one here simply thought I had acquired extra training." She smiled again, more strongly this time. Harry guessed he must be fooling her. "Which was true, after all."

Harry nodded, and said, "Well, I should get going now, before Professor Snape thinks something is wrong." He began edging towards the trapdoor.

Trelawney, to his happiness, let him go. She appeared to be staring off into space and thinking of the past again, her voice distant when she said, "Come back in a few days, before the storm, and tell me your decision. I can help you make arrangements to take the Harry Potter here through the gate."

Harry swallowed the words he wanted to speak, and climbed down the ladder. He couldn't quite bring himself to wave a cheery farewell.

He leaned against the wall of the corridor for a moment when he was down, and closed his eyes. His heart was pounding hard, but almost none of the fear he had felt remained. Even his anger had stopped burning so hotly. It was cold instead, and behind it was determination.

I am going to make it right. No one else will, and someone has to. He lifted his head a little and managed a small smile. And it is what I was born for, after all.

"I—I was just going to ask Professor Trelawney about you."

Harry turned around quickly. Behind him stood the other Harry, staring at him with wide eyes, the tracks of tears on his face.