I just wanted to help him; I guess I should have known that he, like all the others was beyond help.

Twilight had decided that it was in her best interest to keep an inventory of all the guests in Gregory House. She would watch them from as far away as possible and, after she'd seen enough, label them as 'avoid at all costs', 'avoid if possible', 'far gone but harmless', 'far gone and dangerous', or 'alley'. She'd spent what she assumed was a night gathering data.
Fantasy Man: avoid if possible. James: far gone and dangerous. Clock Master: far gone but harmless.
Twilight was bound and determined to find an alley. It was during her hunt that she came across a very strange dog.
He and his son both stood on twos. In addition, they both seemed to be mummified. It was a sloppy job, but it was interesting none the less. Their most interesting feature however, was the weaponry extruding from their heads; an axe from the son's head and a sword from the father's. What's more, they didn't seem aware of the weapons.
"Do you, um, feel alright?" Twilight final asked, unable to hold off any longer. "Well now that you mention it, I've had a terrible headache for as long as I can remember. My boy has the same thing. We think it might be some sort of cold." The mummy dog said.
Twilight would have been baffled, but this wasn't the strangest thing she'd seen in Gregory House. As the mummy dog went about his day, Twilight convinced herself that she could make him an alley. I'll have to remove the sword first, Twilight thought, it's probably what's limiting his brain functions; no doubt it was put there by Gregory.
Twilight wondered briefly if removing the sword would harm the mummy dog in some way, but pushed the thought aside, knowing she could heal any damage.
She waited until the mummy dog wasn't looking; believing it would be easier for him that way, then gripped it with her magic. It took some effort, the sword was snuck deep, but eventually Twilight managed to levitate the blade out of his head.
"How do you feel?" Twilight asked hesitantly. Twilight noticed that his breathing had become erratic. The mummy dog's chest rose and fell sharply.
Before Twilight could ask again, the mummy dog turned. His eyes were glowing red and let out a growl similar to a dog with rabies.
"Daddy, are you alright?" His son asked nervously. The mummy dog let out a roar and reached to strike his son. Twilight magically pulled the son out of the way, and when the mummy dog's paw hit the wall, the wall practically exploded.
The mummy dog roared again and charged out of the room. "What's wrong with my dad?" The son asked. Twilight couldn't answer; she couldn't look away from the path of destruction the mummy dog was leaving in his wake.

The mummy dog destroyed anything that got too close. When Twilight caught up, the mummy dog had his paws wrapped around Gregory's throat.
"P-pleazz my deahr," Gregory choked out, "Hehlp! Puht the serd bahk!" Twilight looked back and forth between the mummy dog and Gregory. For a moment, she considered letting the dog kill Gregory, but knew she couldn't.
"I can't just hurt him!" Twilight said, looking from the sword to Gregory. "Cahn yah reahhly lelt thish keep on!?"
Twilight didn't have time to think it through, so she did the logical thing. She cut the sword back into his head.
The mummy dog dropped Gregory, his eyes returning to normal. "W-what happened?" The mummy dog asked.
"Oh, oh nothing sir, just a little case of a brave girl doing what needed to be done." Gregory said, looking at Twilight with praise.
It had been a complement, but it hit Twilight like a smack to the face.