Have a biscuit,’ she repeated impatiently,

Have a biscuit,’ she repeated impatiently, indicating a tartan tin lying on top of one of the piles of papers on her desk. ‘And sit down.’

There had been a previous occasion when Harry, expecting to be caned by Professor McGonagall, had instead been appointed by her to the Gryffindor Quidditch team. He sank into a chair opposite her and helped himself to a Ginger Newt, feeling just as confused and wrong-footed as he had done on that occasion.

Professor McGonagall set down Professor Umbridge's note and looked very seriously at Harry.

‘Potter, you need to be careful.’

Harry swallowed his mouthful of Ginger Newt and stared at her. Her tone of voice was not at all what he was used to; it was not brisk, crisp and stern; it was low and anxious and somehow much more human than usual.

‘Misbehaviour in Dolores Umbridge's class could cost you much more than house points and a detention.’

‘What do you—?’

‘Potter, use your common sense,’ snapped Professor McGonagall, with an abrupt return to her usual manner. ‘You know where she comes from, you must know to whom she is reporting.’

The bell rang for the end of the lesson. Overhead and all around came the elephantine sounds of hundreds of students on the move.

‘It says here she's given you detention every evening this week, starting tomorrow,’ Professor McGonagall said, looking down at Umbridge's note again.

‘Every evening this week!’ Harry repeated, horrified. ‘But, Professor, couldn't you—?’

‘No, I couldn't,’ said Professor McGonagall flatly.

‘But—’

‘She is your teacher and has every right to give you detention. You will go to her room at five o'clock tomorrow for the first one. Just remember: tread carefully around Dolores Umbridge.’

‘But I was telling the truth!’ said Harry, outraged. ‘Voldemort is back, you know he is; Professor Dumbledore knows he is—’

‘For heaven's sake, Potter!’ said Professor McGonagall, straightening her glasses angrily (she had winced horribly when he had used Voldemort's name). ‘Do you really think this is about truth or lies? It's about keeping your head down and your temper under control!’

She stood up, nostrils wide and mouth very thin, and Harry stood up, too.

‘Have another biscuit,’ she said irritably, thrusting the tin at him.

‘No, thanks,’ said Harry coldly.

‘Don't be ridiculous,’ she snapped.

He took one.

‘Thanks,’ he said grudgingly.

‘Didn't you listen to Dolores Umbridge's speech at the start-of-term feast, Potter?’

‘Yeah,’ said Harry. ‘Yeah ... she said ... progress will be prohibited or ... well, it meant that ... that the Ministry of Magic is trying to interfere at Hogwarts.’

Professor McGonagall eyed him closely for a moment, then sniffed, walked around her desk and held open the door for him.

‘Well, I'm glad you listen to Hermione Granger at any rate,’ she said, pointing him out of her office.