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

Cruciatus Curse’ (he waved a hand towards a witch who was clearly shrieking in agony) ‘feel the Dementor’s Kiss’ (a wizard lying huddled and blank-eyed slumped against a wall) ‘or provoke the aggression of the Inferius’ (a bloody mass upon the ground).
    ‘Has an Inferius been seen, then?’ said Parvati Patil in a high-pitched voice. ‘Is it definite, is he using them?’
    ‘The Dark Lord has used Inferi in the past,’ said Snape, ‘which means you would be well-advised to assume he might use them again. Now …’
    He set off again around the other side of the classroom towards his desk, and again, the class watched him as he walked, his dark robes billowing behind him.
    ‘… you are, I believe, complete novices in the use of non-verbal spells. What is the advantage of a non-verbal spell?’
    Hermione’s hand shot into the air. Snape took his time looking around at everybody else, making sure he had no choice, before saying curtly, ‘Very well – Miss Granger?’
    ‘Your adversary has no warning about what kind of magic you’re about to perform,’ said Hermione, ‘which gives you a split-second advantage.’
    ‘An answer copied almost word for word from The Standard Book of Spells, Grade 6 ,’ said Snape dismissively (over in the corner, Malfoy sniggered), ‘but correct in essentials. Yes, those who progress to using magic without shouting incantations gain an element of surprise in their spell-casting. Not all wizards can do this, of course; it is a question of concentration and mind power which some,’ his gaze lingered maliciously upon Harry once more, ‘lack.’
    Harry knew Snape was thinking of their disastrous Occlumency lessons of the previous year. He refused to drop his gaze, but glowered at Snape until Snape looked away.
    ‘You will now divide,’ Snape went on, ‘into pairs. One partner will attempt to jinx the other without speaking . The other will attempt to repel the jinx in equal silence . Carry on.’
    Although Snape did not know it, Harry had taught at least half the class (everyone who had been a member of the DA) how to perform a Shield Charm the previous year. None of them had ever cast the Charm without speaking, however. A reasonable amount of cheating ensued; many people were merely whispering the incantation instead of saying it aloud. Typically, ten minutes into the lesson Hermione managed to repel Neville’s muttered Jelly-Legs Jinx without uttering a single word, a feat that would surely have earned her twenty points for Gryffindor from any reasonable teacher, thought Harry bitterly, but which Snape ignored. He swept between them as they practised, looking just as much like an overgrown bat as ever, lingering to watch Harry and Ron struggling with the task.
    Ron, who was supposed to be jinxing Harry, was purple in the face, his lips tightly compressed to save himself from the temptation of muttering the incantation. Harry had his wand raised, waiting on tenterhooks to repel a jinx that seemed unlikely ever to come.
    ‘Pathetic, Weasley,’ said Snape, after a while. ‘Here – let me show you –’
    He turned his wand on Harry so fast that Harry reacted instinctively; all thought of non-verbal spells forgotten he yelled, ‘ Protego! ’
    His Shield Charm was so strong Snape was knocked off-balance and hit a desk. The whole class had looked round and now watched as Snape righted himself, scowling.
    ‘Do you remember me telling you we are practising non-verbal spells, Potter?’
    ‘Yes,’ said Harry stiffly.
    ‘Yes sir .’
    ‘There’s no need to call me “sir”, Professor.’
    The words had escaped him before he knew what he was saying. Several people gasped, including Hermione. Behind Snape, however, Ron, Dean and Seamus grinned appreciatively.
    ‘Detention, Saturday night, my office,’ said Snape. ‘I do not take cheek from anyone, Potter … not even the Chosen One .’
    ‘That was brilliant, Harry!’ chortled Ron, once they were safely on their way to break a short while later.
    ‘You really shouldn’t have said it,’ said Hermione, frowning at Ron. ‘What made you?’
    ‘He tried to jinx me, in case you didn’t notice!’ fumed Harry. ‘I had enough of that during those Occlumency lessons! Why doesn’t he use another guinea pig for a change? What’s Dumbledore playing at, anyway, letting him teach Defence? Did you hear him talking about the Dark Arts? He loves them! All that unfixed , indestructible stuff –’
    ‘Well,’