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Professor McGonagall was yelling as she swung from staircase to staircase on a long tapestry, which was in danger of ripping off.
Professors Flitwick, Sinistra, Sprout and Vector were tearing after her, followed by Madam Pomfrey, who was clutching a bottle of Veritaserum, to later force Professor McGonagall to drink and spill the beans of her mystery lover.
They were having trouble however, as the students were aiding her in her escape, as she had promised to owl them her secret later if they succeeded.
However, the desperate teachers were not about to give up, despite fifty crates of Weasley's Wildfire Wizbang being set off in Filch's Office (who came running out with Mrs. Norris in his arms, his and her hair ablaze), threats of burning down the Astronomy Tower (which frankly wasn't saying much as most of the school had been taken care of by the mad fireworks), and dropping banana peels in front of them as they ran pell-mell to catch up with the escaping Professor McGonagall.
"Stupefy!" shrieked Madam Hooch, as she also joined the fight, swooping down on them on a Cleansweep 8.
Her spell missed Ernie, who she was aiming at, but made the ceiling above a couple of fourth years collapse, burying them in marble.
"That's unfair!" wailed Parvati, who had run out of banana peels and was cursing tomatoes to hurl into the face of a passing Professor Sinistra. "We're not allowed to directly use magic against teachers!"
"Then we'll have to take to the next step!" shouted Ron over the banging and hissing of fireworks above them. "Proceed to plan B!"
"What's plan B?" panted Harry, who had given up as he was too tired and had slumped against a statue.
"I don't know! Make anything up!" roared Ron, as he, Luna and Hannah started cursing cheese to grate itself over the heads of the teachers, who were gaining on Professor McGonagall.
Getting up, Harry decided to take action. With Ginny's help, he managed to levitate the giant hourglasses, which recorded the House Points, and made it zoom into the ceiling directly above the frantic teachers who were still trying to fend the crazy students off with various spells and jinxes.
Harry's plan seemed to have worked. The shower of rubies and broken glass had managed to slow the teachers down, but in minutes, Madam Hooch had cleaned them up with a swish of her wand from above.
"We've got to get rid of her!" yelled Ginny, and tried to jinx Madam Hooch, but missed.
"That won't work. We'll have to fight fire with fire. Acio broomsticks!" Harry shouted and with a bang, two broomsticks appeared at their side.
Ginny and Harry quickly mounted and soared upward.
Madam Hooch had noticed, and started hexing torches to create a shield around her.
"I have an idea!" shouted Harry, dodging a Sparkler, which was writing phrases like "Give it up, Sprout!" or "Up yours, Flitwik!"
Harry and Ginny flew side by side until they were right behind Madam Hooch. Harry veered to the left while Ginny flew above them.
"Aguamenti!" shouted Harry and a gush of water squirted out. The water put out some of the flames, leaving a gap in the protective shield. This was Ginny's cue to shout:
"Hidrotis Carbos!" And an oily substance drenched Madam Hooch. Flames erupted on Madam Hooch's shoulder as she shrieked in fright.
Losing control of her broom, she fell off, the broomstick zooming away towards Professor McGonagall.
Engulfed in flames, Madam Hooch fell smack down in the middle of the Great Hall, right in front of the teachers who squealed in fright and fainted.
Harry heard a bang and Professor Snape came rushing in, holding a broomstick. Professor McGonagall nodded from the staircase to him and quick as a flash, they mounted, kicked off from the ground and zoomed out the window, laughing heartily.
Epilogue:
After Ministry investigation, it was discovered that Professor McGonagall had never left in the first place but was found locked in her office, gagged and drugged. And Professor Snape was found playing Exploding Snap with Dobby the house elf.
Harry and Ginny's crime was never found out about, as the soot black body of Madam Hooch was mistaken for a phoenix which had dropped out of the sky, a sign, which Professor Trelawney explained, meant that people born in July were in danger of a sudden violent deaths.
As for the mystery of the two imposters, Harry received an owl from someone he, Ron and Hermione was sure they knew.
The letter read in bold letters:
Nice fight mates. We nicked off some potion from Dung last Christmas. Hope this leaks into the Prophet.
Always up to making a bang,
Professors Not-so-Snape and Wasn't-really-McGonagall