Harry Potter: The Half-Blood Prince's Knight

Snape: “If it weren’t for your mediocre grades and bizarre methods of making potions, I would almost think the Sorting Hat had made a grave mistake by placing you in Hufflepuff rather than my house, given how you’ve been repeatedly challenging the Reasonable Restrictions on Underage Wizards Act and the Code of Conduct for the Use of Dark Magic and Items. I imagine Dumbledore would be astonished to hear of it.”

Talasa replied earnestly, “Professor, do you know what I think? A true Slytherin knows how to keep up a good disguise.”

Snape raised an eyebrow. “Are you saying your house is also just a disguise? A convenient way for you to secretly master the Unforgivable Curses and all sorts of methods for getting close to the Death Eaters?”

Talasa widened his eyes. “Methods for getting close to the Death Eaters? No, no, you’ve misunderstood. I meant secretly raising a group of loyal followers who would swear undying devotion to me.”

This time, it was Snape who froze, his pupils contracting sharply.

This was a Slytherin who had wandered into Hufflepuff.

Talasa: Ambition and elegance are certainly charming, and courage and intelligence are both admirable. But in these turbulent times, I choose to keep my head down and stay safe.