Slowly everyone's memories of the previous night came back. Secretly they were all pleased and enjoyed remembering how hilarious their friends had been when on acid; which they had tortured Fred and George into revealing was what they had put into the punch.

Their anger was first directed at each other…but when it transpired that it was all the twins' fault each friend swore bloody murder and that they would get revenge.

"But how can we pay them back? They are the infamous Weasley twins after all." Seamus said looking around at his friends who were grouped around the common room avoiding each others eyes.

"I have an idea. I say we fight fire with fire. We will launch the biggest prank on the people you would never prank. We are going to prank the Weasley twins." Ginny said triumphantly.

"You're crazy. We can't prank them. No one can prank them." Ron said rounding on his sister.

"There were once four people who would have done. Four people who could have given the Weasley twins a run for their money. Now, luckily, although one has unfortunately died and one also thankfully died at the hands of Harry here, there are two still alive and will be very happy to help us. Also I did hear that McGonagall once joined forces with Snape to teach them a lesson, with very successful results. They also had the help of Harry's mother, the apparently lovely Lily Evans. She had some private grudge with the ringleader and they had a full scale prank war in their last year."

"The Marauders. Of course. Hagrid did say they could give Fred and George a run for their money…or was it the other way around?" Harry said smiling at the thought of his parents and Sirius had told him about the infamous prank war. "Ginny, are you suggesting we solicit their help and recreate their…what was it again? Oh yes…Operation Thong! Where they tied Snape to one of the goal posts in a set of my mother's underpants…in mid winter."

"No. I'm thinking of something McGonagall, Snape and Lily did to the Marauders. But first I'll need to get the details. I know it involves the giant squid somehow."

Snape was unwilling to help them until McGonagall threatened to reveal some of the thing he did at school. She was more than willing to help…the same thing had happened to her while she was at school during this prank war.

"Who's bed did you end up in?" Hermione asked curiously.

"For once Sirius pranked James."

"You slept with my dad!"

"Yes I did, but I don't actually remember it. Unlike you my memory of that night has never come back. Unfortunately." Pause. Silence. "What? Your father was the school stud. Rather like you actually. If you want to hear how we got them back I can tell you but you can't be as mean as we were."

"Awww!" everyone groaned.

"I know…you can be worse. Harry I am going to give you leave to go to Gringots in Diagon Ally. In the back of your vault there is a door with the things your parents hid when they were afraid Voldemort would find them. Their most precious things went into there and one of them was the book. Or rather two of them. One is your mother's diary of her years here. The other is the marauders logbook. Inside it are all their pranks, how they did them and the results and reactions. It also rates each one. There are also some ideas and methods for some new ones they planned to use but never did. How do I know all this you may ask? Well I was a year ahead of them and when I came back after I left to teach I confiscated the book and later I helped them hide their things in the vault. Since it is the holiday you can take the floo network to the bank and spend the day there sifting through."

"Ok, I'll go. But please tell us how you got them back."

Everyone made themselves comfortable as she smiled at them and started telling them.