Harry and Ron hurried along the many passageways of Hogwarts, attempting to make as little noise as possible as they made their way to the library. It was past midnight and even the school prefects and Heads of House (which included Hermione) would be asleep by now but there was still Mrs. Norris to be wary of. She lurked throughout the school the entire night and seemed to sense trouble.

Although Harry had snuck out after hours on numerous occasions since he had come to the school, he was still nervous about creeping about especially when he had been caught plenty of times before. From experience Harry knew that Hogwarts was a very mysterious place and it was easy to find oneself lost no matter how many times you had explored it, even more so when it was dark.

He remembered the time in his first year when he had snuck into the Restricted Section to search for information on Nicolas Flamel and had been so close to being caught due to one of the books screaming at him and alerting Mr. Filch. But this time would be different. He had learnt from his mistakes and would be very careful.

He and Ron were now descending a long stairway made from white marble and luckily it wasn't enchanted to move or it would have taken them a lifetime to get to their destination. They crossed a familiar hall, went through a few doors and finally arrived inside the large library that they visited so often. Making their way noiselessly passed the towering jam-packed bookshelves Ron endeavoured to maintain a grip on the invisibility cloak, which was now a little small for the grown boys and kept slipping off their heads.

At last they reached the Restricted Section, which was hidden at the very back of the library. They carefully stepped over the rope that separated these books from the rest of the library and Ron lit the lamp as Harry began to search for a suitable book for their task.

He studied numerous covers and titles hardly daring to open them in case something screamed out at him again until he came across an old black book titled "Aisling". He pulled it out of the shelf and opened it slowly to the page of contents. 'Hmm, this is interesting.'

Ron looked at him curiously. 'What is it about?'

Harry replied, 'There are some Aisling charms which can either cure nightmares or give someone horrible dreams or particular visions. There are a lot of interesting options. You could give someone a terrible fright with some of these spells.' Harry closed the book and returned it to its original position.

'What are you doing?' Ron asked. He'd been excited by an idea of giant spiders chasing Malfoy around in a dream.

'We can't use that spell on Malfoy.' Said Harry. 'Can you imagine him the day after a horrible sleep? He'd be ever more of a prat than usual.'

'Your right. Then Hermione would start rambling on again about "consequences".' Ron said and rolled his eyes. He couldn't stand Hermione's endless lectures and most of all hated how she was always right (but he would die before ever admitting that to anyone).

Harry searched through two whole shelves, striving to ignore the intense perception that the books were whispering to each other. Ron's nervous twitching beside him was also quite distracting. Despite his efforts, Harry was almost ready to give up. He muttered book titles as he moved along the rows.

'Hang on, what was that last one?' Ron asked.

'Animagus?' Said Harry.

'No, the one before that.' Said Ron.

'Reverse and backfire charms.' Harry carefully removed the book from the shelf and opened the hard cover. 'There's a chapter here for short-term charms. It says here that whoever is under these spells will be influenced against his or her will for twenty-four hours. Some work differently: one will force the person to do the opposite action than intended. The other causes the charm to backfire.' Harry trailed off as he read the following passages.

Suddenly his face lit up. 'Ron! This is perfect. If we put this spell on Malfoy then when he intends to do mean magic to someone it will backfire onto himself and it will effect him instead. Of course we have to pronounce the spell in a certain way to have that specific effect because there are different outcomes.'

'Brilliant!' Said Ron. 'So that way it will look like he is hurting himself and people won't be suspicious, they'll just think he's a complete nutter!'

Harry was beginning to feel quite excited by now. 'The spell seems simple enough so we won't need Hermione after all.'

Ron gathered the lamp, Harry put away any unwanted books and they quietly left the library, glad the search was over.

They hurried back through the doors, up the marble stairs and through many passageways until they arrived at a part of the castle that they had never seen before.

'Just a minute,' said Harry, 'we took a wrong turn. We should have gone right.'

Ron was confused. 'But we never get lost here.'

'I know but everything is harder to recognise since Professor Binns relocated all the paintings. Even some of the suits of armour have been wondering around confused. But that's all right, we just have to go back.' Said Harry.

They returned to the right trail and were about to continue through the next hallway when they heard a movement in the distance.

'Great, it must be Mrs. Norris.' Said Harry.

'Can we ever break the rules without her knowing!' Said Ron in frustration. 'The Marauders Map showed that she was at the other end of the castle before we came down here. It's like she just knows somehow. Typical...'

'Be quiet, Ron!' Harry hissed. 'It might not be her.'

'Who else?' Asked Ron.

'I don't know but I'm not sticking around to find out.' He began to tiptoe away with Ron close behind.

Rounding another corner they found themselves on the track to the Divinations tower.

'Alright, we have to take the long way back from here.' Said Harry. 'I just wish I had have brought the map with us.'

Ron's back was beginning to ache from crouching down for too long under the invisibility cloak. Most boys wanted to be tall but somehow in that moment Ron wasn't very happy about it. Did invisibility cloaks come in sizes? Harry's ancestors must have all been tiny.

'Harry, how much longer?' Ron whinged.

'Not too long, just keep a hold on the cloak.' Harry replied.

Suddenly they heard a clamour of noise in the chamber behind them, which contained many suits of armour.

Harry felt his heart hammer against his chest. 'Someone is coming. Run!'

The boys ran as fast as their legs would take them, hoping that there weren't any insomniac teachers roaming about. Like Snape. Especially Snape.

They ran through some corridors, rushed down a flight of stairs, dashed through a hallway, hurried up another flight of stairs and managed to avoid ending up on the wrong floor.

'Almost there.' Said Harry.

At last they reached the portrait of the Fat Lady. Huffing and puffing, Ron recited the password, ' Pixies.'

The door opened at once and they scrambled into the dark and empty common room where there were only a few embers left burning in the fireplace.

'Thank God.' Said Ron, sighing with relief.

Harry dropped himself onto the sofa, 'I wonder who it was back there.'

'Whoever it was, was obviously following us.' Said Ron.

'A teacher wouldn't have followed us.' Said Harry thoughtfully.

'Then who? Not Hermione.' Said Ron.

'No, not Hermione. I just hope that this person didn't find out about our plan. What if we've been followed all night?' Said Harry with a feeling of unease.

Ron's eyes widened. 'But they couldn't have been. We would have noticed and nobody even knew that we were out tonight.'

'I hope you're right, Ron.' Said Harry, stifling a yawn. 'But we might find out soon enough. After all the noise made in the armour room, Mr. Filch is bound to have heard it and gone to investigate.

'Yes, and then we'll know who it was.' Said Ron. 'Unless whoever it was heard us talking and told Mr. Filch the whole story. But the only teacher other than Dumbledore who knows you have an invisibility cloak is Snape and he won't be able to prove it was us. So we might get away with it.'

Ron looked at the large clock next to the Gryffindor banner on the wall. 'It's after 3am already. No wonder I feel like dropping dead.'

Harry, whose eyelids were already drooping, agreed that it was time to head off to bed and worry about their problems in a few hours.

So they slowly scrambled up to their dormitory and entered, careful not to wake their fellow Gryffindors. Harry folded and put away his invisibility cloak and placed the Spell book beneath it.

The boys didn't even bother to change their clothes and simply slumped into their beds. They were so exhausted that even Neville's snores didn't stop them from plummeting off to sleep at once.