Disclaimer: Don't own Harry Potter. Never have. Never will. I do own the idea to this story, though.
It's a Rock'em Sock'em World
Harry hesitated, glancing over his shoulder at Dobby. "Dobby, are you sure you don't—" he began.
Dobby interrupted him. "No, Master Harry Potter Sir. Dobby is sure. Master Harry Potter Sir and Miss Hermy and Mister Wheezy need Dobby to guard their retreat, Master Harry Potter Sir."
Harry smiled sadly. "Thanks, Dobby. I won't forget this—none of us will. And in case I never see you again—you're a good elf, Dobby, free or no. A good one."
Dobby beamed, his chest puffing up. "Thank you, Master Harry Potter Sir. You is needing to get going," he added.
Harry nodded. "Right." He turned to the fireplace, and, tossing a handful of green powder into the fire, he shouted "Number 12, Grimmauld Place!" and vanished.
Dobby stood with his back to the fire, waiting. He knew it wouldn't be long until the Death Eaters came.
He was right. It was only five seconds after Harry had left that the Death Eaters came bursting through the door. There were many of them—too many, he knew, for him to defeat. The one who appeared to be the leader looked at him, shocked.
"Dobby?" he said incredulously. "Well, never mind, that just makes it easier. Dobby, where did Harry Potter go?"
Dobby shook his head fervently, his ears flapping and the tower of hats on his head wobbling precariously. "Dobby is not telling!"
The leader took a menacing step closer. "That was an order, elf," he hissed.
Dobby crossed his arms. "Malfoy isn't Dobby's Master."
He snarled. "Get aside, then, dammit!"
Dobby shook his head again, then lifted his arms up and, as the building exploded, shouted. "You shall not hurt Harry Potter!"