Fred, George, Percy and Penelope were all congregated in the Gryffindor common room along with Katie Bell and Angelina Johnson [McGonagall let Penelope in – she says that now, it's not House vs House, it's Book vs Book, and everyone in said Book must stick together, no matter who they are], experimenting with Dr Filibuster's fireworks. Since meyerpires needed to be torn apart then burnt, they were creating a firework from Dr Filibuster's that achieved this in one. It was very efficient and saved you 50% of your galleons.
At least, that was what Fred and George were doing. Percy and Penelope were sitting on the floor near the fire, acting cutesy-wootsy [now that the entire series was under siege, Percy decided it was okay to sit on the floor, as long as he was in his pyjamas and not his uniform], in their supposed last moments together. Fred and George looked at this, disgusted. Bored waiting for their friend Lee Jordan, who was off getting supplies for the many combatants, they fired a firework into the direction of the fire [they felt repetition was necessary], and watched gleefully as Penelope and Percy shrieked, Percy loudest of all, and ducked for cover behind the couch.
Angelina, Katie, Fred and George roared with laughter as they saw Lee Jordan come back, his arms laden with merchandise and various supplies.
"Bring it on, glitter boy," grinned Fred.

Madam Maxine and Hagrid stood outside Hagrid's hut. With them was Draco Malfoy, Ginny Weasley, Crabbe and Goyle, Colin and Dennis Creevey and Pansy Parkinson. Accompanying them was Dumbledore, who was smiling over his half-moon glasses, which rested on his crooked nose. Along with their defence tactics, taught to them by Dumbledore himself [there was no point in hiring a Defence Against the Dark Arts teacher, since his normal Headmaster duties did not matter in this particular situation], Hagrid was teaching in a loud voice, as the students assisted in training the magical creatures selected for the fight.
In line were several Unicorns, the purest white, the entire Centaur herd, looking pissed off, dozens of nifflers, contained in a field where they were digging up lost treasures ["So that's where my remembrall went!"], all of the Hogwarts Thestrals, all the dragons from the series [Norberta, the Norwegian Ridgeback, the Chinese Fireball, the Welsh Green, the Hungarian Horntail, the Swedish Shortsnout] with Charlie Weasley standing by, looking nervous.
"Alright, yer gonna have ta – "
"Hagreed, why don't you leet Dumblydore speak?"
"Why?"
"Zee autherr cannot continue to write like dees."
"Righ'." Hagrid nodded to Dumbledore, who looked pleased.
"Excellent. Now, nifflers look for shiny things. We plan this fight on a sunny day, so the nifflers will attack the sparklers. Any questions?"
"What if it rains?"
"Then we make it NOT rain. We're magic, you know!" Dumbledore beamed at them. They set to work, and at the end, they were each given a vile.
"What's this?" asked Cho, looking at it apprehensively.
"Onion juice!" cried Dumbledore, smiling as they all cringed.
"Why?"
"It'll get into your bloodstream, so long as you drink it every night until the fight. Don't you read Louis Sachar? Vampires hate onions."