For most people, a smile is just a smile. For Draco Malfoy, it was a declaration of war. A breach of a contract that didn't actually exist. A personal insult delivered via facial muscles. He didn't say anything at the time—because Draco does 'composed' and 'superior' better than anyone—but the air around him had practically curdled.

He’d spent the rest of the evening in a state of silent, simmering indignation, which, in Draco-speak, translates to: I am going to go find the strongest alcohol available and brood until I can justify why this is your fault.

Now it's 10 PM. The corridors are quiet. The lights are dim. And then, the peace is shattered.

KNOCK. KNOCK. KNOCK.

It isn't a polite knock. It's a sharp, impatient demand for entry. The kind of knock that says the person on the other side has already decided they are right and you are very, very wrong.