A short fic written for a gif prompt: (Gifset not mine. Available upon my A03 page for this story))
The sounds of smashing glass drew the attention of every male in the room. Human, angel and demon alike turning just in time to see the familiar besuited body of The Doctor slam into the cold marble floor, cuts and bruises decorating his usually flawless face.
A look of concern grew upon John's face as he watched the motionless time lord, worry sprawling through him. "Doctor?" he voiced, taking a small step closer, his instincts to treat beginning to take hold of him. The man may not have been human but he had damn well become a friend in the short time he'd known him and he was going to do what he could.
Ice filled his veins as the brunette raised his gaze mere seconds later, his once bright and lively eyes replaced by cold, black, emotionless holes. Demon. He knew it before the creature spoke, his friend's voice stolen by the soulless evil now contained within.
"I am not the Doctor" the haunting voice spoke, catching small flinches from the former soldier nearby. The human obviously still coming to terms with the idea that the supernatural was real, and even more alarming, that the character of his favourite tv show was truly alive. And yet no fear was detected off him, irritating yes, it was great fun killing those scared of demon's. Those that begged for their lives as the blade of the knife brushed the thin membrane above their pulsing carotid artery.
As If it wasn't enough that they had to help that son of a bitch Crowley escape from a criminal mastermind but now this. Tilting his head in irritation Dean met the gaze of his possessed friend. "A demon possessing an alien. Great". The sarcasm earning him a frustrated glare from Castiel.
Within seconds the sound of several guns cocking crackled through the room, the tension in the room tangible. "Good evening Crowley" The demon Doctor cooed pointing the stolen colt at the visibly worried king of hell. Amusement grew within as he caught sight of the guns that had been in turn raised at him. He knew it was a pointless gesture, this vessel could easily survive a gunshot, his boss had assured him of that.
A small amused burst of laughter rose from the corner, the tall frame of the genius detective unfurling himself from the counter top he'd settled upon. "Moriarty sent a Lord of Time to kill the King of Hell. Neat" he retorted, unable to halt the impressed smile from rising upon his lips. John glanced over to his flatmate, shaking his head incredulously. At the mercy of supernatural forces and that bloody git is impressed!.
Bloody great failures. Hiring the Winchester's and their band of useless cohorts had been scraping the bottom of the barrel, every other avenue expended. He turned to meet the eyes of the renegade demon, now under the control of the one soul that dared to battle him for control of hell. The same man who'd created a civil war down below. An Armageddon in the pit. The onrushing end.
"Jim sends his love"