Bound by the headmaster's spell, Harry stared mutely in shock as the jet of green light erupted from Snape's wand and hit Dumbledore's chest, blasting the old wizard into the air. For a split second he seemed to hang suspended beneath the shining skull, and then he fell backwards, over the battlements and out of sight. Harry refused to believe what he had just seen. Was this a trick? But how...?

‘Out of here, quickly,' ordered Snape, seizing Draco Malfoy by the scruff of the neck and forcing him through the door. Suddenly Harry realized that he could move again, and it was in that moment that the truth hit him. The green light had been no trick, it had been real. Dumbledore had to be dead, otherwise he still wouldn't be able to move. Snape had killed Dumbledore, he really had...

Half in a daze, he saw the other Death Eaters who had watched Dumbledore die hastily leave the tower, and from down below he heard Snape shout, ‘It's over, time to go!'

His professor's voice brought him back to his senses. No, the murderer would not leave the scene of the crime so easily; he would see to that! He sprinted down the spiral staircase, down to the lower levels where the fight was still raging, though the death eaters were retreating.

Harry had no interest in the fighting: his only aim now was to get to Snape before the man could leave the school's anti-Apparition wards. As he was stil wearing his invisibility cloak, no curses were aimed directly at him, but he still had to duck several that were flying around. Once he reached the door, he roughly pushed aside an astonished Death Eater and ran down the corridor. There were more steps to take and in his hurry, he tripped on his invisibility cloak and fell down the last steps. Cursing, he jumped up and grabbed the cloak that lay beside him. He didn't bother to put it on again; it just slowed him down anyway. Instead, he tossed it into an empty classroom and banged the door shut. He would fetch it later after he had dealt with Snape.

Finally he left the castle and ran towards the gate. Draco must have already disapparated, but Snape was still there, obviously waiting for his Death Eater friends. Harry could hear theír footsteps behind him. He didn't bother to turn around though; reaching Snape was all that mattered now.

When he heard a female voice yell a curse behind him, for a fraction of a second he thought he had made a grave mistake, then he heard a dull noise at his back and an invisible force abruptly threw him to the ground. Right next to him, a bush erupted into flames. 

Harry groaned. His knees and elbows hurt from the fall, but he was otherwise unscathed. Had that woman missed him and hit the bush? But what had been that strange sound at his back? Had someone cast a shield spell for him? Were the Order members already here too?

‘No!' He heard Snape yell at the witch from up ahead of him. ‘Have you forgotten our orders? Potter belongs to the Dark Lord! We are to leave him! Go! Go!! You, too, hurry up!' he shouted at the other Death Eaters.

Luckily for Harry, they listened to Snape and rushed past him, though one didn't miss the chance to give Harry a kick in the side as the teen struggled to rise.

By the time Harry had finally scrambled to his feet, the Death Eaters had disappeared - all but one. Snape's lonely silhouette could still be seen right beside the Apparition barrier.

Why didn't he disapparate as well? Harry wondered briefly, then quickly covered the short distance that separated him from Snape. Just as well; he won't get away so easily!

‘Sectumsempra!' he yelled, waving his wand wildly, but Snape deflected the spell with a quick flick of his own wand.

‘You dare use my own spell against me, Potter?' he hissed dangerously. ‘It was I who invented it  -  I, the Half-Blood Prince!'

The revelation only served to infuriate Harry more.  You are the Half-Blood Prince? You invented that spell and then thrashed me mercilessly for using it? You bloody hypocrite! ‘Stupefy!' he yelled, and another red jet of light flew at Snape, but the man again blocked the spell easily.

‘You will never win a duel if you don't master nonverbal spells, Potter!' Snape spat.

Don't you dare lecture me now! I hate you, and I really think I can do this now. I definitely mean it, and to hell with its being illegal, Harry thought as he shouted. ‘Crucio!'

For a moment he thought he had succeeded, but at the last moment Snape managed to erect a shield and the curse was deflected. However, Harry refused to give up, and opened his mouth for a second try, when suddenly his wand flew out of his hand and, to his utter horror, was caught by Snape. Yes, Snape was extremely apt at nonverbal spells; he had demonstrated this numerous times in the classroom.

‘No Unforgivables from you, Potter!' Snape commanded. ‘You have neither the ability nor the nerve!'

Well, maybe not, thought Harry angrily, at least not now that I am disarmed, but that doesn't mean I won't keep fighting!  Fists raised, he flung himself at Snape Muggle-style, but a Jelly-Legs Jinx dropped him to the ground. He cursed and spat out mud. There was no way he could stand up, but he raised himself to a sitting position and glared at Snape who had approached and now stood less than five feet from him.

Was this the end? He was as defenceless as Dumbledore had been less than twenty minutes ago. Would he now meet the same fate at the hands of the same man? Harry's heart hammered, but it was out of hatred for Snape and his betrayal, not out of fear. ‘Kill me, then,' he panted. ‘Kill me like you killed him, you coward!'

Snape's facial features contorted in rage. ‘Never - ‘ his wand whipped through the air  ‘-call me a -‘  another whipping movement of his wand followed, this time in the opposite direction ‘-coward!' he hissed furiously.

Harry cried out in pain, and his hands flew to his face where livid welts on both cheeks burned tremendously.

The sharp pain cut through Harry's rage, allowing him to think more rationally.

Harry glanced at his fingers. He was surprised there was no blood on them given how much his face hurt. But Snape obviously hadn't injured him seriously. Harry couldn't help but feel bewildered. He had tried to Sectumsempra and Crucio the man, and all that Snape did in return was to use a Jelly Legs Jinx and Expelliaramus, but when he called the man a coward, that caused him to lose his temper and lash out?

Besides, Snape couldn't deny it, Dumbledore had been defenceless, and, what's more, he had trusted Snape and never suspected what he had planned. Harry stared accusingly at Snape again. ‘Dumbledore trusted you absolutely,'  he said tonelessly.

‘Yes, Potter.' Snape's voice was no more than a hoarse whisper. ‘He did.'

‘How could you?' Harry's voice broke. He felt completely overwhelmed. During the past weeks he and Snape had managed to treat each other civilly, even respectfully. And then, just a few hours ago, he had suffered a huge shock when Sybil Trelawney revealed Snape's role in the murder of his parents.

Yes, he had realized that by performing his spying duties Snape was atoning for fatal decisions in his past, and he'd even felt a certain sympathy for his teacher, but those crimes had always been something abstract. Learning that Snape was directly responsible for his own parents' deaths had suddenly made that past a lot more personal and a lot harder to accept.

Still, Dumbledore had managed to convince him of Snape's ignorance as to who the prophecy was about at the time and his subsequent deep regret when he had realized what his actions had caused. It had been hard for Harry to accept, and had it not been for their changed relationship he would never even have considered trying to see things from Snape's perspective, But he had in the end and he had promised Dumbledore to try not to let this revelation affect the trust he had managed to develop for Snape. And now this. The ultimate betrayal.

‘And I trusted you, too,' he said in a low voice and swallowed. A lump was forming in his throat, and he realized that now that his wild rage had disappeared, grief was setting in. It was not only grief for the loss of Dumbledore, the most important mentor and the closest thing to a grandfather he had ever had, but also grief about a betrayal by yet another person whom he had trusted. The fact that it had been such hard work to build that trust only intensified the feeling of loss.

‘I did what had to be done,' Snape said quietly, meeting his eyes, ‘as you will have to do one day, Potter.'

Harry stared at him, surprised by Snape's answer. He had expected Snape to sneer at him and ridicule him for his stupidity in trusting the wrong person, but this was... odd. Snape was almost talking as if they were still on the same side, but this didn't make sense...

Dumbledore's words shot through his mind, I will tell you this now, and I want you always to remember: with Professor Snape there is much that is not as it seems.

‘Professor Dumbledore trusted you absolutely,' he repeated slowly, desperately trying to organize the whirling thoughts in his head. Could Dumbledore have been so wrong? He had been so sure. Again he heard the echo of the headmaster's words: I would trust Severus Snape with my life; in fact I am sure the day will come where I will place my life in Professor Snape's hands.

And he did, Harry thought bitterly. He trusted him with his life, but Snape didn't protect it, he took it instead! Then a wild thought crossed his mind. Could it be that Dumbledore had misled him with his words? That the Headmaster had in reality meant just that? But why should he want Snape to do that?

Imagine yourself in Professor Snape's position. You are a spy, and that means that you always have to act like a true Death Eater, had been Dumbledore's words. Yes, Dumbledore knew that if Snape killed him, it would once and for all resolve all doubt concerning Snape's loyalty to Voldemort. But to let someone kill you just to protect their cover, that was pure madness!

Still, Dumbledore was a bit mad, and his attitude towards death was ... well, different. What had he said to Voldemort a year ago? Your failure to understand that there are things much worse than death has always been your greatest weakness... And back in first year, Ron had stated that Dumbledore was off his rocker when Harry had quoted the headmaster's words: After all, to the well-organized mind, death is but the next great adventure.

Yes, thought Harry desperately, that might be true for you, but you left me! I need you! The feeling of immense loss tightened his throat. He suddenly wished that the theory he had about Snape's loyalty could be true, so that at least Snape  would be still there to be counted upon. He opened his mouth and almost asked Snape, but then closed it again without saying anything. What answer did he expect? And what answer could he believe? Silently he scrutinized Snape, searching for answers in his eyes. The man didn't evade his gaze. He, in turn, considered Harry musingly.

‘And I am sure, Mr Potter,' said Snape deliberately, ‘that when the time comes, you, too, will be able to do what needs to be done.'

Harry swallowed hard. Snape had just addressed his biggest fear, the one he had hidden from his friends all year. Yes, he had shared with them the details about the lessons with Dumbledore, the memories and the horcruxes, but the thought that had always been at the back of his mind, was, that once all the horcruxes would be destroyed, he would still have to meet Voldemort and kill him.

Yes, Ron and Hermione knew that, and they had been supportive, wondering together with him what advanced defence techniques Dumbledore was going to teach Harry so that he would be up to the task. But even if he were technically able to defeat Voldemort, what if he couldn't bring himself to kill someone, even Voldemort?  Harry had never confessed to them this fear of his own weakness at the crucial moment, and now Snape was addressing it and expressing such confidence, in fact, he was the only person ever to do so.

The sound of voices startled him out of his thoughts and he saw a group of people coming out of the castle. Snape raised his wand. Harry had his gaze fixed on him but didn't flinch.

‘Finite.' Snape undid the Jelly-Legs Jinx and threw Harry's wand to him. Harry caught it, but didn't try to curse the other man again.

He was so confused he didn't know what to think. He should probably try to delay Snape until the Order members arrived, but what if they killed Snape before they had a chance to find out where Snape's true loyalties lay?

But was there even a question at all, or it was just wistful thinking that he - and Dumbledore - hadn't misplaced their trust?

Harry felt precious time running out as he stared desperately into Snape's face. For a brief instant he had the impression that Snape wanted to say something, but the man remained silent, his gaze fixed on Harry. Then, with a stiff nod to him, Snape turned on the spot and disapparated. Harry stared doubtfully at the empty spot. He was sure he would meet the man again. All he could do was hope that when that time came, they would be on the same side.