This is the first chapter of an imaginary episode from "Harry Potter and the Half-Blood Prince". Harry is at Hogwarts and the second war is beginning to escalate. After delving into Snape's memories in the pensieve last year, Harry finds a growing psychic link with his least favourite teacher. What will he discover about Snape's secret past – and his current motives?

Chapter One (of Three)

Harry Potter sat up suddenly in his four poster bed. It was still dark and the wind was blowing hard against the castle walls and making the windows shake. He used the sheet to wipe sweat from his forehead, and sat up, drawing his knees to his chest and hugging them. He looked through the small gap in the curtains at Ron, who was shuffling and snuffling under the covers, trying to get comfortable, until just a tuft of his ginger mane was visible. From somewhere in the corner, another boyish voice murmured something about broomsticks.

Harry reached for his wand from under his pillow and whispered, "Lumos Minima," causing a warm ethereal glow to spread out around him. He put on his glasses. By the soft light he could see Ron's bed more clearly, and the heap of clothes on the floor; lying where they'd fallen a few hours ago. It had been a tough practice game, even by Quidditch standards, and the two boys had had little enough energy left, without having to put away their clothes. Ron was sleeping soundly now, and Harry hesitated. It seemed unfair to disturb him, but his best friend had been adamant that Harry should wake him if he had the nightmare again. The morning would be too late; the details were likely to fade, and with them, the meaning of what the dream contained.

Harry slipped out of bed and stepped carefully across the pile of discarded robes, socks and underwear until he reached Ron's bed. He gently pulled back the quilt and exposed his friend's eyes, nose and finally his entire face to the light of his wand. He watched as Ron blinked and grumbled himself back to wakefulness and then, finally stared up at Harry with a look of concern in his eyes.

"Did it happen again?"

"Yep"

"How far did you get this time?"

"A lot further... I think I know where they're taking him."

Ron raised an eyebrow and patted the bed beside him. Harry climbed up alongside and positioned himself so they could talk in whispers.

The dream that had disturbed Harry for at least six or seven nights since they'd returned to school was the subject of fascinated speculation between the three friends. Hermione claimed to be convinced that Harry was seeing something that had serious meaning for all of them. After all, his dreams last year had led them to the discovery of the Prophecy, and had also helped to save Mr Weasley's life, if only just in time. She'd told Harry that his latest nocturnal vision must also be loaded with significance, and she had given strict instructions that the two boys should write down every detail for her to think about. As Harry began to describe to Ron what he had just witnessed, neither boy reached for a quill; it would take too long and the pleasantly spooky feeling they were sharing would be lost.

Harry's dream always centred on none other than Professor Sirius Snape, their least favourite teacher in the whole of Hogwarts. That was why it seemed crucial to discover more of its meaning. Many years ago Snape had been a Death Eater – a follower of Voldemort himself, but now worked within the Order of the Phoenix as Dumbledore's trusted spy. Beyond finding him abrasive, no-one else seemed to have a problem accepting Snape's loyalty to the cause of Right and Good. Perhaps it was just that Harry, Ron and Hermione had come to despise him as a cruel and bullying teacher, and that Snape returned their animosity in spades, that the three of them couldn't quite bring themselves to trust him. Any opportunity to discover anything duplicitous about his actions or intentions was too valuable to ignore. That was why finding the meaning of the recurring dream had become so important.

"Well," said Ron, "where did he end up?"

Harry wriggled himself into a more comfortable position.

"A prison cell, but it wasn't Azkaban."

"Huh, well at least that figures," Ron snorted, "so, if they were locking him up at the age of fourteen or whatever he was, how come he's allowed to teach at Hogwarts? There must be some sort of law about teachers not being criminals, surely."

Harry shook his head in the semidarkness.

"He wasn't being locked up in the prison Ron, he was a visitor."

The silence that followed told Harry that his explanation meant nothing to Ron.

"He was going to visit his dad – he was the one locked in the prison cell."

"Okay then, Snape's old man is a crook..."

"It's worse than that Ron; I can't say how for sure, but for a moment or two I could almost feel what Snape was feeling. Like, because he was just a boy, it's easier to get inside his mind. Not like now, with all his skills in occlusion."

"So what was going on? Were they planning to throw away the key on Snape Senior?" Ron whispered, propping himself up on his elbow to look at Harry.

"I think it's worse than that. I think he was seeing his father for the last time. It was his final visit before – his dad's execution."

Ron sat straight up and turned to Harry. Even in the poor light, Harry could tell that Ron was staring, concentrating hard, and trying to figure it all out.

"It could be possible. They don't execute people now, but I remember Mum and Dad talking about whether we should go back to the death penalty days. I was surprised Dad was in favour. He said that the dementors were worse than death itself, and we just use them so we don't have to face the messy job of punishing bad people ourselves."

"But the dementors' kiss...?" began Harry.

"You don't die," Ron interrupted, his voice dropping very low, "but they rob you of your very soul! I can see what Dad means. He told me that the dementors were only brought to Azkaban about twenty five years ago, before then; you could still be put to death."

Harry thought hard to remember the final details of his dream. Snape's emotions had been strongest just before the vision had faded. He'd experienced the fear as he walked along the damp, echoing prison corridor, and then, when he'd reached his father's tiny cell, young Severus had been overwhelmed by horror. His father raised his face and looked straight into his son's eyes, but there was only the slightest glimmer of recognition. Mr Snape looked far older than Harry had expected, with a large scar across his chin, extending down his neck and onto his bare chest. He shared his son's hooked nose and lank, black hair. Finally, Harry had watched the older man smirk, take aim, and spit generously onto the floor of his cell. Then he turned away from Severus, walked to his bunk, and lay down with his back to his trembling son. Neither of them had said a word.

As Harry lay there and recounted the last of the details to Ron, he felt in need of the comfort of just being close to another human being. In spite of everything he'd put him through in over five years at Hogwarts, Harry began to feel sorry for Snape.

(That's it for now – if you like it, I'll write the next chapter. Leave me some feedback and I'll try to upload soon!)