"150 things I will not do: written by M Mcgonagall" by 18

Rule 145 : If the thought of a spell makes me giggle for longer than 15 seconds, I am to assume that I am not allowed to do it.

What Caused Rule 145 to be made

Harry sat in the library contemplating once again why he had elected to come back to Hogwarts for his final year. His elbows were propped up on the table and his head was resting on the table with his hands covering his head. For the moment it was peaceful but he knew it wouldn't last. So why oh why did he agree with Kingsley that he should get his NEWTS before he started working with the Aurors. He heard someone enter the library but he didn't bother looking up until they sat with a thump in the chair opposite him. He looked up into the angry face on one Hermione Granger.

"I can't believe you gave him the idea for that." she growled. She would have yelled but they were in the library.

"Not intentionally." Harry confessed, "I'm not even sure what idea I gave him. I wasn't really paying any attention to what he was talking about ."

"McGonagall is looking for you." she sighed in exasperation, "Why does this kind of thing always happen when you're involved?"

"I wasn't involved." he stated emphatically, "I didn't do anything. I can't even think that what I said could have given him any ideas. I was talking about classes."

"You can't hide in here forever." she pointed out, "McGonagall will find you."

"All the more reason to stay put and hide." he dropped his head back onto the table.

"What exactly happened?" she wanted to know.

"Well, I'm not exactly sure." He said looking up again, "I was sitting in here with a few transfiguration books trying to prepare for tomorrows class. You know I'm really interested in doing the animagus transformation and I want to get all my questions outlined. I'm even using the homework planner you got me." he pointed to the book.

"Oh." she grinned but it turned into a frown, "Didn't I give you that one back in fifth year?"

"Yes and I am using it." he grinned, "Anyway I was just sitting here studying for class and he walked up and sat in the same chair you're sitting in. He started jabbering right away but I was in the middle of something and didn't want to stop. And let's face it Seamus doesn't usually have anything important to say so I didn't think anything of it."

"True enough even if it is a bit rude." she frowned at him, "But I guess he was being rude not waiting until you were finished so he deserved it."

"Right so I finishing a few notes I was writing down he said something about Transfiguring McGonagall into an owl. I'm not sure what exactly he said as I was kind of ignoring him. But I didn't want him to hurt her so I said, that won't work. I told him an animagus can't be transfigured into any animal except their animagus form without hurting them."

"Oh Harry." she said, "I don't know what he asked but the idea you inadvertently gave him was…"

"That's not the worst of it." he admitted, "After I said that he started giggling."

"Seamus giggled." she dropped her own head into her hands, "That explains a lot."

"I know. But he sat there and giggled for like twenty or thirty seconds before he jumped up and ran off. Well of course when he started giggling I looked up and saw the look on his face." Harry shuddered, "I knew right then I was going to be in a lot of trouble for whatever he decided to do. To try an avert some of the blame I stayed right here. I hoped that this would keep whatever detention I'm handed just a little smaller since I didn't physically help. I really didn't mean to help him at all."

"Oh Harry." Hermione sighed again then stood, "Come on."

"Do I even want to know what he did?" he asked refusing to budge from his spot.

"No." she walked around the table, grabbed his arm and hauled him up, "But you need to come see it. Maybe you can help restore some order and get a smaller detention."

Harry packed up his bag and slung it over his shoulder before following Hermione out of the library and through the school. They didn't run across a single student or teacher.

"Where is everyone?" Harry asked concern evident in his voice.

"You'll see." she replied.

"It seems a bit too quiet around here." He commented, "Was anyone other than you left out?

She stopped him just before they crossed in front of the Great hall, "I think I was the only one who didn't drink the pumpkin juice this morning. I had a headache so I opted for tea even though it's very warm today. I'm assuming that was how but really I'm not sure."

Harry took a deep breath before stepping past Hermione to look into the Great Hall. It actually took him several moments to process what he was seeing. His mouth dropped open and he gaped at what was happening in the hall.

"I'd really like to know how he did it." Hermione stepped up beside Harry.

Seamus was at the top of the hall with the professors trying to look contrite. However the wicked grin he flashed at Hermione and Harry told them he wasn't the least bit sorry.

"Seamus Finnegan." Professor McGonagall gained his attention again, "What in the world gave you the idea that this would be a good prank."

"It was Harry's idea." he stated pointing at the boy who had just entered.

"Mr. Potter." she started.

"Oh no." Harry yelled, "Not my idea. I didn't know what he was going to do. I don't know how he got this from what I did say."

"He did give me the idea." Seamus argued, "Just not word for word."

"Don't blame this on me." Harry shook his head then repeated the story of how Seamus came to him in the library, "I knew when he started giggling I was going to get blamed for something."

"Well at least you can help us figure out how to change them back." she huffed realizing it really wasn't Harry's fault.

"What did you do?" Harry asked looking around, "I mean how did you do it?"

"It will wear off tomorrow morning on its own." Seamus tried to get them to leave the rest of the students.

"No way Mr. Finnegan." Professor McGonagall yelled, "I am not going to chase after animals for a whole day. You tell us how you did this and we'll fix it now."

"Well it's rather complicated." Seamus stated.

"Then how did you get it done in just under an hour?" Harry pushed the cat that was rubbing on his leg away carefully.

"I put a spell on the benches to transfigure everyone into the animagus form they can become. I took your advice and only changed them into the animal they could become so no one would get hurt. I picked lunch as a good time." he grumbled, "Don't know how I missed Hermione though."

"I had just stood up to go find Harry for lunch." she admitted, "I figured he was still studying."

"A finite should fix it then." Professor Sprout suggested.

"On seven hundred animals, this is going to take a while." Professor Flitwick started, "Too bad we can't find the seventh years and change them first then they could help with the rest."

"Finite." Seamus pointed at a cat near him but nothing happened, "Uh oh."

"Finite." the teachers tried and got the same results.

"Finite." Hermione yelled.

By this time the animals began to realize they were going to be stuck this way and the uproar started. Squeeks, squeals, barks, bellows, roars and screeches filled the room. The professors tried to calm the animals down and Hermione pushed the doors shut so not one could leave. The animals in the room continued the uproar and some moved on Seamus.

"Ow." Harry looked down to find a white ferret going for a second bite, "Wingardium Leviosa."

He grabbed the ferret as it floated up and he handed him to Hermoine, "He bit me so you better hold him before I wring his neck."

Hermione grabbed him by the scruff of the neck, "You didn't try to undo the spell yet."

A cat ran up his leg causing another yelp from Harry. It was nothing compared to what Seamus was going through. Cats were climbing his legs, birds of all kinds were dive bombing him and other animals were growling at him but keeping back.

"I thought you'd be happy to get out of a day of classes." Seamus yelled climbing up on a table.

As another cat tried to run up Harry's leg he bellowed, "Finite Incantatum!"

Twenty pops transformed the students nearest him back into students. Including the blond ferret in Hermione's hand who changed into a frowning Draco Malfoy. Two birds were in the air and when they transformed back the students started to fall. Harry quickly threw out cushioning charms for them.

"All birds land." Harry ordered.

" Well it looks like you have your job cut out for you Mr. Potter. Let's have groups of twenty surround Mr. Potter. Make sure they leave room to grow." she instructed the teachers and then turned to the student animals, "Attention everyone, I am instating a new rule. Mr. Finnegan you will write this new rule one hundred times as the first part of your detention. As follows: If the thought of a spell makes me giggle for longer than fifteen seconds, I am to assume that I am not allowed to do it."

Harry was exhausted by the time he finished turning everyone back. Madam Pomfrey healed the ferret bite and provided him with a pepper up potion so he wouldn't miss any classes. Seamus was still writing but had been treated for several bites, scratches and pecks.

"How many points did he lose us?" Dean asked frowning at his friend.

"I believe that any points he lost were replaced by Mr. Potter when he fixed it all." Flitwick suggested looking at the other teachers who nodded in response.

Harry was feeling better when the teachers released the students to go to afternoon classes. Seamus, however was still writing his lines. Harry smiled at Headmistress McGonagall who was standing over Seamus. He then flicked his wand at the boy and left for class. When Seamus made it to their class half way through the period he was sporting purple robes, his hair was spiked and pink and he had 'I am an idiot written across his forehead.

"Harry please take it off." Seamus interrupted the defense professor. Who was trying to hold in a laugh.

"No." he replied, many students in the room were also trying not to snicker.

"I promise I will never try to blame my prank on you again." he stated.


"I promise not to turn everyone into animals?" he asked, Harry shook his head, "What?"

"You must promise to leave me alone when I am studying and not take things I say and make pranks out of them no matter how tempting." Harry growled.

"Fine." Seamus huffed.

Harry waved his wand and the pink hair and purple robes disappeared. However he left the hair in spikes and the words on his forehead, "Those will be gone by tomorrow morning."

"She gave you fifteen points." Seamus grumbled as he went to find a seat.