Hermione looked at her watch and sighed.

'Harry's very late,' she said, glancing at the trapdoor where Harry was supposed to have appeared thirty minutes ago. 'If he's not here in twenty-five minutes, the potion's not going to work.'

Ron looked down at the bubbling green contents of the cauldron. An eye floated to the surface of the potion and gave him a steely glare. He shuddered.

'Are you sure about that?' Ron said. 'Because Seamus said – '

'Seamus doesn't know what he's talking about. A Death Potion can only work over a certain amount of time,' Hermione said. 'Besides, he's not very good at Potions, is he? The last time I checked, he liquified his cauldron.'

Ron sniggered, stopping only when a second eye emerged from the cauldron's depths.

'Ugh, I wish they'd stop doing that,' he said in disgust. Hermione waved her wand and the two eyes disappeared into the green potion with a loud pop.

It was night time and Ron and Hermione were at the top of the Astronomy Tower, waiting for Harry to arrive from his usual detention with Professor Snape. Snape liked prolonging the detentions, especially with Harry. That's because he hated Harry.

'I'm freezing,' said Hermione, stretching her hands out towards the fire that roared beneath the cauldron. It was a winter night and snow lay in patches around them. A cold wind was blowing relentlessly and bit their faces. 'I should have brought my fur coat.'

'Here, take my jacket,' Ron said, taking it off and holding it out to her. She took it and wrapped it gratefully around her.

'That's better,' Hermione sighed.

'How long d'you think it'll take that thing to crack?' Ron said, nodding at something behind Hermione.

'I don't know,' Hermione replied, closing her eyes, trying not to think about the 'thing' that lay covered entirely, imprisoned tightly in a dark cloak behind her. It had been squirming weakly all this time but when it heard itself being mentioned, it started twiching rather violently.

'Oh, where is Harry?' she moaned, and she surprised Ron by jumping to her feet.

'Calm down, he'll be - hey! Where are you going?' Ron added when Hermione started walking towards the trapdoor.

'I can't stand being close to that thing for another minute. Come on, we're going to get Harry.'

'But he's in detention! With Snape. There's no way we'll get him out of there.'

'I don't know how we'll do it; we'll lie and say McGonagall needs all Gryffindors in the Common Room or something,' Hermione said desperately.

Ron looked at her disbelievingly.

'Hermione Granger lying to a teacher?' he snorted. 'Wow. Is it really that bad?'

'No, it isn't, Ron,' Hermione said irritably, sarcastically. 'Now get in here, please.'

She pulled the Invisibility Cloak from within a pocket and spread it out in front of her so that Ron could get under it first.

'Wait, what about the Hevera?' Ron said, looking at the fidgetting creature.' We can't leave it here by itself, it could somehow ruin the potion and we won't be able to kill it.'

'Petrificus Totalus,' Hermione muttered, her wand pointed at the Hevera. It stopped moving at once.

'There,' she said. 'Can we go now?'

Ron looked uncertainly at the motionless Hevera, shrugged and went underneath the Cloak.

'You're the boss,' he said, as they opened the trapdoor and descended the spiral staircase.

They didn't even bother to close it.

TO BE CONTINUED NEXT WEEK…