Had you or I been in that particular corridor on that particular night, we would have noticed nothing amiss. Just a plain corridor with a few chips in the walls and a few scuffs on the floor. But had a poltergeist, or something like him, been there, he would have seen a beautiful, troubled girl who was hurriedly making her way toward you. Her bright red hair was tied back in a pony tail, and she was always looking behind her, even though she knew no one could see her. Her pretty face was contorted with a mixture of fear and sadness; however, there was someone in that particular corridor on that particular night, and it wasn't a poltergeist or something like him. Being invisible, one would think that Ginny might be able to avoid such wandering persons, but she was to distracted and distraught to notice anything else around her. So Ginny ran straight into her.
The Professor immediately drew back and pulled her wand from beneath her nightgown, which had flowers that were actively blooming on it.
"Incarcerous!" she shouted. Ropes flew from her wand and wrapped themselves around Ginny, who fell to the floor with a surprised high pitched yelp.
"Well, I thought you were Peeves, who by the way has caused so much trouble tonight that I think he might want a talking to from the Baron, but apparently you aren't that nuisance of a poltergeist."
"Professor McGonagall, it's me, Ginny Weasley..." Ginny's last words barely passed from her lips as the ropes McGonagall had cast upon her were slowly getting tighter.
"Oh, goodness! I'm so sorry Ginny!" Professor McGonagall exclaimed as she charmed the ropes from Ginny's body. "Although I am glad that you aren't Peeves or some meddling Slytherin, I'm afraid I must ask you what you are doing roaming the corridors with a disillusionment charm on you at one in the morning."
Ginny saw no other option but to tell the truth. "Professor, a few of my friends and I are on a mission to steal the sword of Gryffindor from Snape's office."
Shock flitted across McGonagall's face, but it was soon replaced with a mischievous smile. "Well, under different circumstances Miss Weasley, I would deduct a great deal of house points and send you back to your dorms immediately, but these are hard times, and you know what? I don't even recall bumping into you a few minutes ago."
It took a while for this to register with Ginny. "Thank you so much Professor," she said breathlessly.
"It was nothing, dear. Have a good night!" McGonagall said as she continued to make her way down the corridor.
Ginny picked up her journey in the opposite direction, almost not believing how lucky she was.
Invisibility turned out to be an asset for the trio, but it also caused a few awkward moments. For instance, when Seamus first arrived at the gargoyle in front of the headmaster's office, he ran into Neville, which ended with both of them falling on the floor, Seamus on top of Neville. After both of them scrambling to their feet and some muttered apologies, they both stood in awkward silence, waiting for their leader to arrive.
Another awkward moment happened when Ginny arrived on the scene. She was also running, and she also ended up colliding with the pair of boys, sending the trio once again toppling to the floor, this time with Ginny on top of the two boys.
After much whispered apologizing, Ginny said, "Okay, are we on time?"
"You know, I think that was the one flaw with your plan Ginny. I bet you didn't realize that you wouldn't be able to see these watches that are synced to each other when our entire bodies are disillusioned, right?" Seamus asked.
"Oh. No I didn't realize that. Oh well, let's just get up into the office and get the sword," Ginny said, and the trio turned toward the gargoyle.
"Um... I know that you don't really like the people who have taken over here, and we are on a mission to overthrow said people, although we need access to the headma..." Before Ginny had even finished her sentence, the gargoyle had sprung aside so fast that Seamus thought a fire might have been lit underneath it.
The three students rushed into the office and opened the door as quietly as they could. What they saw was completely different than what they expected. Instead of skulls, ancient crumbling tomes, or other evidence of dark magic, Snape's office was completely clean, and utterly empty. Not one thing adorned the tables or his desk, and not one book occupied the many bookshelves around the walls. It looked as if not one person had set foot in this room since Dumbledore had walked out for the last time.
Ginny saw their prize sitting behind Snape's desk in a glass case. She whispered for Seamus and Neville to follow, and the trio tiptoed behind the massive desk. Ginny drew her wand from beneath her robes and whispered, "Silencio," and then, "Diffindo." The glass casing caved in silently, and then Seamus disillusioned the sword and handed it to Neville. Had they been able to see each other, they would have been able to see the smiles of triumph plastered across each other's faces. The three students crept as quietly as they could out of Snape's office, almost not daring to breathe, but wanting to burst with celebration. Had they kept constant vigilance, as one of their Defense Against the Dark Arts teachers once said, they might have avoided the next sequence of events.
"Incarcerous." The voice that came from behind them was so penetrating and so evil that the ropes that knocked them to the ground might not have been necessary.