The old routine, once again. The usual sarcasm in Potions class, the intimidation when they met in the hallways. But somehow, Harry knew. He couldn't prove it, but he guessed it. Snape had cast a Memory Charm on him. Nonetheless, the spell hadn't erased the notion that something very important had happened that day. He remembered riding the unicorn and then... a strange blank, which wasn't exactly Nothing. It was a blank full of... of what? Something indefinable. The most intriguing of all had been Snape's detached behaviour as he provided Harry contact with the beautiful animal although he was incapable of enjoying the experience himself. However, since then Snape had denied that pleasant image before Harry every day. In other words, Snape was still a mystery, and becoming more and more so.

There was no one able to help him. Ron wouldn't understand. He wouldn't dare tell Hermione either that he had irresponsibly run to the Forbidden Forest or the reasons that had led him to it.

As for Dumbledore... In the first Occlumency lesson scheduled after the scene with the unicorn in the Forest, Harry had stepped into the Headmaster's office and told him he didn't feel he was in the psychological condition to have those classes at the moment. He had made this statement with such coldness and disdain that Dumbledore seemed to understand it would be useless to insist. Strangely, he hadn't asked, as Harry had expected, if he would accept going back to being taught Occlumency by Snape.

All that irresolution and isolation was getting on Harry's nerves. At first, he had become distracted, absent. Friends and teachers noticed it and asked him what was the matter. He told them it was nothing, or only admitted to be tired of not doing anything while a war raged on.

He still coached Dumbledore's Army and practised Quidditch. Those were the only activities that diverted his mind from the mortal boredom of Hogwarts.

The work on Slytherin's Manuscript progressed slowly. A storm seemed to be forming between them. Harry couldn't focus on anything, and that deeply irritated the teacher.

"What's that horn on the mantel for?"

"Potter, concentrate on the code, or we will never be done deciphering all the phonemes."

"Is it asking too much to have the answer for one simple question?"

"It's a ptyx."

"???"

"It's the one object capable of containing the Nothing. Do you know the Nothing, insolent brat? It's never pleasant to become acquainted with the Nothing..."

Obviously, Harry didn't know what to say to that. He returned to his helpless silence and to the deciphering of cryptic codes.

In Potions class, at Harry's distracted behaviour, Snape tortured him more and more. The teacher's pressure at least made Harry feel a little more alive... Dangerously, Harry started provoking him.

"Potter, haven't I told you time and again not to add the asphodel before the mixture turns purple?"

"No, sir," Harry retorted.

"What did you say?"

"No, you didn't say any of that! Now, if you want to take points from Gryffindor, it's not my fault, there's nothing I can do about it, you're going to take them anyway, aren't you? Why do I have to keep up this act of black humour comedy?"

The entire class exchanged astonished looks. The same terror appeared in the eyes of Slytherins and Gryffindors. No one dared to challenge Snape that way. Even Draco Malfoy was too perplexed to display one of his ironic smirks.

The Potions master came to stand less than ten inches from Harry. "Mr Potter, go look for Mr Filch immediately and tell him you're in detention. Get out of here right now. And if you do not go to Mr Filch, the Headmaster will be informed of your behaviour."

The sun was about to set when Harry finished cleaning the last bathroom, the one for the Prefects. He could no longer stand the ammonia smell of the detergent Filch had given him. He was about to climb the stairs toward the Gryffindor Tower when he found... Snape.

The Potions master's gaze at that moment seemed to puncture him. Adding to the usual hatred, there was now deep hurt and rancour. "Be at my office at eight o'clock, after dinner."

At the scheduled time, there they were, in Snape's office.

"This time you went too far! Don't talk back to me, I have nothing to discuss with you. You don't deserve my patience in listening to your gibberish. In front of the school you've already served your punishment. But I'll be demanding from you an extra task. Write me an essay about the association between Potions and Dark Arts. Sit at this desk and get to work. You will only be allowed to leave when the essay is complete. And if you are thinking about disobeying me, tell me at once so I can take you to the Headmaster immediately."

Without saying a word, Harry sat on the high-backed chair where the teacher usually sat.

Snape placed a roll of parchment, a quill and a pile of books in front of him. "I selected these books for you to begin your research. They are all basic texts, hopefully not beyond your level. But if you have any doubts they fail to clarify, or if you would like to deepen the research, my library..." With a large gesture he indicated the bookshelves around them. "...is at your service."

Before withdrawing to his private quarters right behind the office, Snape stopped to collect Ceci from her enclosure and took her with him, leaving Harry alone with the books.

The first book Harry opened was Dark Potions. The book reported that there were equivalents to almost all the dark spells in the form of potions. Harry scribbled some notes in his parchment. Wasn't it incredible? There was, for example, a potion that offered the wizard the power to utterly control another, similarly to the effect of the Imperius Curse. Naturally, the book didn't include recipes, otherwise Snape wouldn't have handed them to Harry. In Potions of Chaos, wizards of an ancient order of Dark Magic, the Order of Chaos, narrated their experiences with potions that, according to them, were the best way to control the ungovernable force of Dark Magic, which normally spreads indefinitely in all directions. And in The Alchemical Potions Book - which wasn't strictly a Dark Arts tome -, there were impressive reports of how potions could alter the user's personality. Harry began to understand why Snape was so... severe, so demanding in his classes. There weren't only the risks from a possible mistake in the brewing. The wizard's concentration also made part of the process, so he had to learn to control himself.

Suddenly, Harry heard a door click open. He raised his eyes from the book and saw Snape leaving his chamber with an expression of excruciating pain on his face, holding his left arm. He saw him walk to the mantel and rummage for something. "Potter, I have to go out. I will leave you here with your research. When you are finished, just close the door behind you and the wards will reset themselves. Don't leave anything behind because, once you're out and the door is closed, you won't be able to come back in."

"It's Voldemort, isn't it?" Harry asked, worried.

Snape looked away, in a very unusual gesture. "Tomorrow we will talk about your essay," was all he said before hurrying out.

After Snape was gone, Harry couldn't concentrate on the research anymore. He wondered why Voldemort would have called Snape, what could be possibly happening. Again, Harry rebelled against the fact of being left in the dark. How would he be able to defeat Voldemort if he was always kept out of the game?

Unfortunately, there wasn't anything he could do at the moment. He did his best to focus on the essay.

Those books revealed that there was a strong connection between Potions and Dark Arts. Perhaps that was what Snape was trying to show him: that if he paid more attention to his Potions studies, he would indirectly learn some Dark Arts resources.

When Harry finished the task, he glanced at his watch. Midnight. Absorbed in his research, he had lost track of time. Midnight and Snape hadn't come back yet. Uneasy, he gazed at the base of the lamp that cast light on his parchment. It was an onyx statuette of Anguish with her arms raised toward the sky, holding the lamp - the only source of light in the dusky room. The office seemed empty and meaningless without Snape. That was the utter Dark. The death of the Phoenix. Harry started to panic, pondering the idea that Snape might not come back and not managing to bear it. He stood up and paced around the empty salon. On the mantel... no ptyx! Had Snape taken it with him? The one object capable of containing the Nothing... But the Nothing, right now, seemed to fill this place entirely. And if Snape didn't come back, that horrible Nothing would fill Harry's soul as well.

In a corner, at the back of the office, the scrying mirror, round, concave, totally dark, except for one reflection... of a golden gleam. Where had that gleam come from? From the north window? Certainly the dungeon windows didn't open to the outside of the castle, but maybe there was something in the inner courtyard that caused that gleam? No. It was more likely to be the reflection of the golden frame of the mirror itself, where unicorns assaulted a nymph with blazing flames. The mirror's dark wings closed over the agonising golden gleam, leaving nothing but the reflection of the nymph's dead body, less and less discernible. Nevertheless, amidst the vague mist surrounding the nymph's corpse, all of a sudden... the seven stars of Ursa Major, the septuor, scintillated, and an ethereal song took over the salon.

At that moment, Harry turned to the door and saw Snape. Everything seemed to merge in a vortex of emotions. He remembered the kiss, the intensity of that instant, and now all that returned, combined with other sensations. His heart was beating fast. He remembered everything now, and Snape was there, alive. Alive but, Harry noticed then, covered in mud and blood.

The septuor and the whole range of emotions dominating Harry reflected in Snape's eyes. Before he could quite understand what he was doing himself, Harry had flung himself into the older wizard's arms.