Harry and Hermione hunkered down behind the toilet, Ron joined Dean behind the sinks, and Ernie hid around the corner in the cul-de-sac shaped room. On the other side of the door one of the Death Eaters muttered something. The lock clicked. The Death Eater swung the door open, saw Malfoy's body, and immediately shouted, "Protego!" performing the Shield charm. What he didn't count on was that one of the targets would be clutching a shotgun. Dean fired, the Shield didn't protect against physical attacks, and the Death Eater yelled and was blown backwards like a rag doll. As Dean recocked the other four launched various curses through the door, Ernie just managing to duck around the corner when his curse rebounded off the other Death Eater's Shield charm. The Death Eater cast a spell of his own and a massive snake surged out of his wand tip and slithered into the room. Harry spoke Parseltongue, directing the snake backwards at the Death Eater, who screamed and banished the apparition. Ernie cast another spell at the man, but he was quick enough to block it again, and Ernie was quick enough to dodge it again. The Death Eater screamed, "In!" and his backup platoon of troglodytes charged forwards.
The five of them had their hands full keeping themselves from being overrun. Three troglodytes dashed into the room nimbly, and Dean blasted them to the ground with one shell. As he recocked the others cast cruel curses to kill the other troglodytes who ran in. The party patiently slaughtered all of the troglodytes who made their way into the room, until soon the troglodytes had to climb hand over hand to get over the pile of corpses in front of the door, which made it even easier to dispatch them. At last all the troglodytes were dead, and Harry could hear only the Death Eater's ragged breathing outside the door. The Death Eater, using great skill, Vanished all the corpses with one wave of his wand. Dean stealthily padded over next to the door, and nodded at Ron, gesticulating strangely. Ron got the message, nodded, and gesticulated at Ernie. Ernie got it and nodded too. He stuck his head around the corner. "Anyone left alive?" he asked loudly.
The Death Eater bellowed, "AVADA KEDAVRA!" Ernie just dodged the deadly green curse. Dean pivoted around the corner very quickly and pulled the trigger, only getting a glancing blow on the Death Eater because of his haste. Even so the man's wand arm was blown off and bounced away. The Death Eater shrieked in agony. Dean aimed at his head and pulled the trigger. The shotgun was out of shells. He painstakingly reloaded the shotgun as the Death Eater sagged against the wall, holding his stump of an arm. The other four came out after him, looking at him pitilessly.
"Please," he begged, "I'm not a threat anymore, I've lost my arm, just let me go."
Harry snorted. "No, I've seen Voldemort give Wormtail his arm back, he'd do the same for you. So you still are a threat. But not for long." Harry grabbed the shotgun off Dean and shot the Death Eater right in the mask, instantly reducing him to biological waste material. He gave the shotgun back, and Dean loaded in another shell.
Harry saw two manticores fly through a closed window at one end of the corridor. "Time to leg it!" he announced and ran. Everyone ran after him, Dean acting as rear guard.
Four mountain trolls pounded around the corner ahead. Harry didn't even blink before he let off an Impediment jinx, and the other members of the party struck the trolls in a similar fashion so the trolls were all out of commission. A giant spider and two Blood-Sucking Bugbears came around the corner.
Harry had been taught how to deal with Blood-Sucking Bugbears. He and Hermione cast a special spell at the same time, causing a pond of blood to erupt out of their wands. The Bugbears should have immediately flung themselves to the ground and lapped up the blood, dying in seconds when the poison in the fake blood took effect. Instead they ignored the great lake of blood they were now stepping over, unheard-of among Blood-Sucking Bugbears. So instead the five of them attacked manually, putting lots of curses and lead shot at the Bugbears. The two were killed very quickly. Then two of the sorcerers cast Stunners simultaneously, knocking down the spider, while a third Vanished all the blood so they could run through without slipping over.
"Up the stairs!" Dean shouted. "The manticores are catching up!"
"Gotcha." Harry agreed and ducked into a slim spiral staircase leading up. He spied through the next door several soldiers so he continued climbing. But the soldiers had seen him, and fired loads of rounds through the doorway, taking down Ernie. Dean, the next one through, fired his shotgun indiscriminately, wounding two of the soldiers and killing two more. He emptied the shotgun, and had no more ammo, so he dropped it, drew his Desert Eagle and ran on. He dropped a grenade behind him as he caught up with Harry. The soldiers also threw a grenade in. When the two grenades went off, they structurally damaged the staircase so much that a large section fell away from it, not only crushing dead a manticore who'd been shimmying up the stairs but also stopping chase from the soldiers.
Meanwhile Harry had come to the next and final floor the staircase led to and was looking about with despair. He saw shadows of magical creatures of all kinds nearing both ends of the corridor he was in. He knew they couldn't try and take on all these things, and rightly guessed they couldn't go back down the stairs for the wrong reason (i.e. he thought the soldiers would give chase, as he didn't realise the staircase had partially collapsed). They couldn't just hide in a classroom, they'd have to hide someplace the creatures wouldn't find them. And for a second he couldn't think of one. And then he grinned.
"Right, everyone, follow me." he whispered. Harry walked over to the blank stretch of wall where the Room of Requirement lay waiting, invisible. Harry walked past it three times, thinking, 'We need a comfortable, soundproof place that can't be seen by people and creatures who want to kill us.' And after the third time, the doorway suddenly appeared. Harry wrenched open the doorknob and barged in, the rest of his party coming in after him.