"Winner's keepers, Malfoy," Potter replied back, sensing he was outgunned. "So, why didn't you all run?"
"Stop talking and give up, Potter!" Crabbe sneered loudly.
"Why would I?" Potter shot back, readying his wand.
Draco felt ill at the idea of fighting. "No! The Dark Lord wants Potter alive!"
"Shut up, coward!" Goyle hissed.
"You really are a bitch," Crabbe said, glaring at him, disgusted.
Draco went red. His "friends" knew what his punishment was. "But...."
"You and your da are done!"
Potter used that opportunity to attack, and Granger and Weasley showed up. Crabbe and Goyle started cursing everything they could. Draco ducked out of the way and stunned Goyle when he tried to kill Granger. Crabbe swore at him but then cast the Fiendfyre spell, and magical fire exploded out of his wand.
Draco knew they were dead but ran anyway, climbing onto the bookcases to get higher. He magicked Goyle to safety, but the flames collapsed the bookcase Goyle was on and he fell into the flames. The heat and smoke were overwhelming. The air was super hot, but before he could try to save himself, Potter came back for him on a broomstick.
Draco couldn't believe it, and grabbed Potter's hand. Potter heaved him up and behind him and, in the commotion, Potter dropped his mother's wand into the flames.
"Shit," Potter swore. "Hold on!" Potter turned away from the door and into the flames.
"What are you doing!?" Draco screamed.
Potter ignored him and flew through the smoke. He coughed as he searched for the target. Draco applied the Bubble Head Charm to both of them, so they could see and breathe, again.
"Thanks," Potter shouted, as he turned downward to collect the tiara-like thing off a bust. Then Potter flipped the broom back toward the door at full speed as flames roared behind them.
Draco saw they were heading to the hallway wall at full speed and shouted, "Arresto momentum!"
They still hit hard and fell to the floor. Thankfully, Granger cast the doors shut.
"Holy Merlin!" Weasley yelled.
"That was Fiendfyre! That was so dangerous! They both are gone," Granger said, aghast.
Draco wasn't upset that they were gone. Both had been gloating about his punishment and nearly took advantage of him, as his punishment was known to all. Death Eaters, including both their dads, had taken their turn. Blaise had made sure they didn't try to take him, though. 
Draco watched the Horcrux melt and only somewhat listened to the Golden Boy and his minions discuss it and the bloody snake. However, fighting down the hall drew Granger and Weasley to help, and he was left alone with Potter.
Potter eyed him, cautiously. Draco couldn't keep eye contact with anyone nowadays. Fear was his constant companion. Potter seemed to be assessing him, somehow able to see through his glamours. Draco couldn't look at him, coward through and through. Potter, however, glanced back to his friends, worriedly. His hand open and closed as he fretted, empty-handed. Potter was defenseless again.
Well, fuck. Potter needed a wand. Potter was about to leave when Draco touched his arm, and Potter looked back into his eyes. It almost physically hurt, but Draco slowly held out his wand, his only defense, for him to take, hoping, praying with all his might that Potter would win.
"What?" Potter gasped, looking shocked at his offer.
"Finish him... please...."
Potter took the wand and double-checked that he hadn't changed his mind. "What happened to you?" Potter asked, but Draco looked away.