'Ah, Evans, don't make me hex you,' said James earnestly.

'Take the curse off him, then!'

James sighed deeply, then turned to Snape and muttered the counter-curse.

'There you go,' he said, as Snape struggled to his feet. 'You're lucky Evans was here, Snivellus — '

'I don't need help from filthy little Mudbloods like her!'

Lily blinked.

'Fine,' she said coolly. 'I won't bother in future. And I'd wash your pants if I were you, Snivellus. '

'Apologise to Evans!' James roared at Snape, his wand pointed threateningly at him.

'I don't want you to make him apologise,' Lily shouted, rounding on James. 'You're as bad as he is.'

'What?' yelped James. 'I'd NEVER call you a — you-know-what!'

'Messing up your hair because you think it looks cool to look like you've just got off your broomstick, showing off with that stupid Snitch, walking down corridors and hexing anyone who annoys you just because you can — I'm surprised your broomstick can get off the ground with that fat head on it. You make me SICK.'

She turned on her heel and hurried away.

'Evans!' James shouted after her. 'Hey, EVANS!'

But she didn't look back.

'What is it with her?' said James, trying and failing to look as though this was a throwaway question of no real importance to him.

'Reading between the lines, I'd say she thinks you're a bit conceited, mate,' said Sirius.

'Right,' said James, who looked furious now, 'right — '

There was another flash of light, and Snape was once again hanging upside-down in the air.

'Who wants to see me take off Snivelly's pants?'

But whether James really did take off Snape's pants, Harry never found out. A hand had closed tight over his upper arm, closed with a pincer-like grip. Wincing, Harry looked round to see who had hold of him, and saw, with a thrill of horror, a fully grown, adult-sized Snape standing right beside him, white with rage.

'Having fun?'

Harry felt himself rising into the air; the summer's day evaporated around him; he was floating upwards through icy blackness, Snape's hand still tight upon his upper arm. Then, with a swooping feeling as though he had turned head-over-heels in midair, his feet hit the stone floor of Snape's dungeon and he was standing again beside the Pensieve on Snape's desk in the shadowy, present-day Potion master's study.

'So,' said Snape, gripping Harry's arm so tightly Harry's hand was starting to feel numb. 'So . . . been enjoying yourself, Potter?'

'N-no,' said Harry, trying to free his arm.

It was scary: Snape's lips were shaking, his face was white, his teeth were bared.

'Amusing man, your father, wasn't he?' said Snape, shaking Harry so hard his glasses slipped down his nose.

'I — didn't — '

Snape threw Harry from him with all his might. Harry fell hard on to the dungeon floor.

'You will not repeat what you saw to anybody!' Snape bellowed.

'No,' said Harry, getting to his feet as far from Snape as he could. 'No, of course I w — '

'Get out, get out, I don't want to see you in this office ever again!'

And as Harry hurtled towards the door, a jar of dead cockroaches exploded over his head. He wrenched the door open and Hew along the corridor, stopping only when he had put three floors between himself and Snape. There he leaned against the wall, panting, and rubbing his bruised arm.

He had no desire at all to return to Gryffindor Tower so early, nor to tell Ron and Hermione what he had just seen. What was making Harry feel so horrified and unhappy was not being shouted at or having jars thrown at him; it was that he knew how it felt to be humiliated in the middle of a circle of onlookers, knew exactly how Snape had felt as his father had taunted him, and that judging from what he had just seen, his father had been every bit as arrogant as Snape had always told him.