Theodore Nott was shaking. He didn't want to be sworn to the Dark Lord.
It wasn't that he was disloyal. He was plenty loyal - to his friends and family.
Draco hadn't seemed to find any good in being Sworn.
Theo's bastard of a father hadn't found any, either. Theo treated him on the regular for torture.
His father stubbornly refused to say a word against the Dark Lord.
Theo had heard - it was only a wisp of a rumor - that you couldn't be sworn into the Dark Lord's service unless you were faithful. He'd detect it and kill you outright. Theo couldn't decide if that was better than slow and agonizing torture (and, of course, the fun of murdering Muggles). If the rumor was true, Theo would be dead come morning. He couldn't flee - there was no one to flee to. Only Zambini had managed to escape ruddy England, and his mother murdered men for a lark and profit.
Severus Snape appeared in the doorway, looking the same as he ever had - grave, ashen, and that peculiar sort of dour that flashed to acerbic on the regular.
Expressionless, Snape looked at Theo, watching him pace. After several minutes had passed, Snape said only, "When a Slytherin kneels..."
Theo looked dully at his Head of House, the only sign of recognition a spark in his eye, "He has only begun to fight."
Theo stopped pacing. He nodded to Snape, and they walked towards the Dark Lord's audience hall (do not call it the ballroom, Theo's treacherous mind snarked).
While Theo walked (one half-step behind Potions Master Snape), he remembered the stories Snape had told around the common room. They had always started the same way, with a Slytherin kneeling before one who was unworthy (the reasons varied). The schemes were complicated, and sometimes didn't work out very well. That wasn't the point, really. The point was that they weren't Gryffindors, who would die rather than kneel to the unworthy. That a Slytherin knew that snakes liked nothing better than to bite hands that were feeding them. Slytherins ought not to bow, particularly not to someone unworthy...
Theo's eyes flicked up to Snape's back. How long had he been thinking thus? These stories had started when they were in first year, or earlier (none of the older students had seemed surprised).
They reached the Dark Lord's Chamber.
Theo suppressed every thought except, "When a Slytherin kneels, he has only begun to fight." He layered over it a passion to feel Granger bleed - she was the most obvious Muggleborn, it was expected. He followed it with bloody, gory descriptions his father had given him.
Snape knew, deep in his heart, that to swear to serve the Dark Lord, you could have no doubt that it was the right thing to do.
Theo knelt, and swore, and screamed, when the Dark Lord seared his Mark into his flesh.
[a/n: Now, read the title again. Because the easiest lie to believe is the one you desperately want to be true.]