Severus Snape glared around at the third-year Charms class he was supposed to be teaching.

Never again. Never again, no matter how ill Flitwick was, no matter how earnestly Dumbledore insisted that no one else was qualified and available. Dumbledore could come down here and teach the bloody class himself if he couldn't find another substitute, because Severus was never, ever, going to teach Charms again for as long as he lived.a

It had been entertaining, at least, to teach Defense Against the Dark Arts last year, even if the students were all deplorably ignorant (Granger didn't count). And he had taken the opportunity to get Lupin back for the Boggart incident, by teaching the class how to recognize werewolves. After that, it was only a matter of time until someone worked it out. And despite interference from Black, that part of the plan had worked out nicely. Lupin was gone.

But this — this was positively infuriating. A third-year class ought to be able to perform a simple Cheering Charm when given such precise instruction, but so far only one or two people had succeeded. Mostly Ravenclaws — the Gryffindors were hopeless.

"Watch your aim, Mr. Creevey, if you miss the target it'll be ten points from Gryffindor for being a pathetic excuse for a wizard. You are thirteen years old, not eight. And despite a vast amount of evidence to the contrary, I have been told that you are quite intelligent. Prove it."

Colin Creevey gulped and continued trying to hit Ginny Weasley with a Cheering Charm. "Laetifico!" he squealed, over and over. "Laetifico! Laetifico!"

Severus grimaced. He could not wait until the boy had learned nonverbal magic. But there were other students to attend to — he stalked between pairs of students grimacing in frustration, pointing out the considerable number of mistakes they were making, intimidating them until they rectified the mistakes.

He stalked back toward the front of the classroom, growling at nothing in particular. Creevey still hadn't succeeded — stupid boy — and Weasley was still standing there, waiting for him to get it right.

"Laetifico!" Creevey tried again, and this time he succeeded. The filament of white light leapt from the tip of his wand — it missed Weasley by barely a millimeter — it continued on and hit Snape, square between the eyes.

Looking aghast, Creevey lowered his wand and started apologizing profusely. Everyone else in the class, however, was staring silent and astonished at their professor.

A grin was spreading slowly over his face. Severus could feel it happening, and he relaxed into the delightful warmth of just being happy. He looked at his class.

"Whatever are you sorry for?" he asked of Colin. "I have never felt so happy in my life. Class," he went on, gazing around with an air of delight, "I believe that you all deserve a little time off to prepare for the holidays. Dismissed."

The students all gaped at one another, looked worriedly at their grinning professor, and then began to slowly pack up their things and file out of the door.

"Go on, go on," Severus prodded gently. "Have some fun. You've earned it."

Ginny and Colin hung back.

"What are we going to do?" hissed Colin, glancing sideways at Professor Snape. "He'll be furious when he snaps out of it, I'll get several detentions at least and probably lose about thirty House points."

Ginny nodded seriously. "I would suggest a Finite Incantatem, but Hermione said that doesn't work on something that only affects a person's mood. What we need is some kind of countercharm." She grimaced. "Oh, I wish Hermione was here!" Feverishly, he began paging through her Charms book, looking for something that might reverse the effects of a Cheering Charm. "We've got to do it quick, before any of the other students or staff see him, because he'll never forgive us if they see him like this. Bloody hell," she added in an undertone, "there are too many charms! I'll never find the one we need in time!"

"Well, there's always the Depressing Charm," suggested a dreamy voice from behind them. Ginny turned.

"Luna! I didn't notice you there. Anyway — what's this Depressing Charm? Sounds kind of depressing."

Luna smiled vaguely. "It's meant to make people sad, but since Professor Snape is always sad, I don't think it will do much besides take away the cheerfulness."

Colin frowned. "Professor Snape is always angry, not sad."

Luna looked at him thoughtfully. "He's angry because he's sad," she told him. "Something quite dreadful must have happened to him, so he tries to hide inside his anger rather than seem vulnerable. It's quite a horrible thing to do, but I don't suppose he can help himself."

Ginny raised her eyebrows at this unusual assessment of Professor Snape's character, but nodded. "Well, it sounds like it would work — the charm I mean," she added. "Do you know it?"

"Oh yes," Luna said happily. "I've had to use it on occasion, in fact. Here." She pulled out her wand. "Tristifico. There, that should do it."

And all of a sudden, Snape was glaring at them as usual. "Miss Lovegood, Miss Weasley, Mr. Creevey, I believe I dismissed this class? Why are you all still here?"

Colin opened his mouth to explain, but Ginny stomped on his foot and he shut up. "Sorry, Professor, we're leaving now," Ginny said, ushering her friend out of the classroom. Outside the door, she turned and grinned at them. "Nicely done, Luna. And I have to say, Colin, even if it did get us in trouble, that was an impressive Cheering Charm. Never thought I'd see Snape actually smiling."

Colin grinned and nodded. "And I hope," he added with uncharacteristic solemnity, "that I never have to see it again."

A/N: So...I am bad at writing humor. But the idea came into my head recently - what would happen if someone hit Snape with a Cheering Charm? - and it wouldn't leave me alone, so I had to write this, no matter how boring it is. Forgive me.