Harry Potter 06 - Harry Potter and the Half-Blood Prince

the music was inside him, not without: it was his own grief turned magically to song that echoed across the grounds and through the castle windows.
    How long they all stood there, listening, he did not know, nor why it seemed to ease their pain a little to listen to the sound of their mourning, but it felt like a long time later that the hospital door opened again and Professor McGonagall entered the ward. Like all the rest, she bore marks of the recent battle: there were grazes on her face and her robes were ripped.
    ‘Molly and Arthur are on their way,’ she said, and the spell of the music was broken: everyone roused themselves as though coming out of trances, turning again to look at Bill, or else to rub their own eyes, shake their heads. ‘Harry, what happened? According to Hagrid you were with Professor Dumbledore when he – when it happened. He says Professor Snape was involved in some –’
    ‘Snape killed Dumbledore,’ said Harry.
    She stared at him for a moment, then swayed alarmingly; Madam Pomfrey, who seemed to have pulled herself together, ran forwards, conjuring a chair from thin air, which she pushed under McGonagall.
    ‘Snape,’ repeated McGonagall faintly, falling into the chair. ‘We all wondered … but he trusted … always … Snape … I can’t believe it …’
    ‘Snape was a highly accomplished Occlumens,’ said Lupin, his voice uncharacteristically harsh. ‘We always knew that.’
    ‘But Dumbledore swore he was on our side!’ whispered Tonks. ‘I always thought Dumbledore must know something about Snape that we didn’t …’
    ‘He always hinted that he had an iron-clad reason for trusting Snape,’ muttered Professor McGonagall, now dabbing at the corners of her leaking eyes with a tartan-edged handkerchief. ‘I mean … with Snape’s history … of course people were bound to wonder … but Dumbledore told me explicitly that Snape’s repentance was absolutely genuine … wouldn’t hear a word against him!’
    ‘I’d love to know what Snape told him to convince him,’ said Tonks.
    ‘I know,’ said Harry, and they all turned to stare at him. ‘Snape passed Voldemort the information that made Voldemort hunt down my mum and dad. Then Snape told Dumbledore he hadn’t realised what he was doing, he was really sorry he’d done it, sorry that they were dead.’
    ‘And Dumbledore believed that?’ said Lupin incredulously. ‘Dumbledore believed Snape was sorry James was dead? Snape hated James …’
    ‘And he didn’t think my mother was worth a damn, either,’ said Harry, ‘because she was Muggle-born … “Mudblood”, he called her …’
    Nobody asked how Harry knew this. All of them seemed to be lost in horrified shock, trying to digest the monstrous truth of what had happened.
    ‘This is all my fault,’ said Professor McGonagall suddenly. She looked disorientated, twisting her wet handkerchief in her hands. ‘My fault. I sent Filius to fetch Snape tonight, I actually sent for him to come and help us! If I hadn’t alerted Snape to what was going on, he might never have joined forces with the Death Eaters. I don’t think he knew they were there before Filius told him, I don’t think he knew they were coming.’
    ‘It isn’t your fault, Minerva,’ said Lupin firmly. ‘We all wanted more help, we were glad to think Snape was on his way …’
    ‘So when he arrived at the fight, he joined in on the Death Eaters’ side?’ asked Harry, who wanted every detail of Snape’s duplicity and infamy, feverishly collecting more reasons to hate him, to swear vengeance.
    ‘I don’t know exactly how it happened,’ said Professor McGonagall distractedly. ‘It’s all so confusing … Dumbledore had told us that he would be leaving the school for a few hours and that we were to patrol the corridors just in case … Remus, Bill and Nymphadora were to join us … and so we patrolled. All seemed quiet. Every secret passageway out of the school was covered. We knew nobody could fly in. There were powerful enchantments on every entrance into the castle. I still don’t know how the Death Eaters can possibly have entered …’
    ‘I do,’ said Harry, and he explained, briefly, about the pair of Vanishing Cabinets and the magical pathway they formed. ‘So they got in through the Room of Requirement.’
    Almost against his will he glanced from Ron to Hermione, both of whom looked devastated.
    ‘I messed up, Harry,’ said Ron bleakly. ‘We did like you told us: