Wilson was picking up a prescription at the pharmacy when he saw Cuddy heading towards her office. He broke away to intercept her, hoping to discuss a radical new treatment plan he was exploring for an end-stage patient, but his rehearsed speech was cut off mid-sentence when Cuddy pushed open her office door and narrowly avoided being drenched by a bucket of water.

"House!" Cuddy hissed, and Wilson decided it would be prudent to continue the conversation later.

He stopped by her office after lunch, but the phone rang just as he walked in, so he hung back, trying to give her some privacy. Instead of a polite greeting, however, Cuddy yelped and dropped the receiver. She held up her hand, which was smeared black.

"What the hell is this?"

Against his better judgment, Wilson stepped closer. "Shoe polish, I think."

Cuddy glared at him, and he stepped back again. "I'm going to give you the benefit of the doubt and assume the timing of your visit is just a coincidence," Cuddy said, though she clearly considered him guilty by association. "Go tell your partner in crime that the next incident will cost you five clinic hours each."

"How is that fair?" Wilson protested. "I didn't have anything to do with this. And punishing me isn't going to stop House. It might even encourage him."

"Maybe it will encourage you to stop him before you both get into more trouble." Cuddy pulled out a tissue, only to discover it was the last one in the box.

Clearly, a hasty retreat would be the best course of action. After a quick detour to confirm a suspicion, Wilson stalked into House's office, ignoring the closed blinds. House was hunched over his desk, trying to shove a stack of paper into a three-hole punch, his fingertips suspiciously smudged.

"Somebody put shoe polish on Cuddy's phone while she was at lunch," he said, torn between outrage and amusement. "You wouldn't happen to know anything about that, would you?"

House looked up, a picture of wide-eyed innocence that raised the hairs on the back of Wilson's neck. "Me? Do I look like someone who owns shoe polish?"

"I don't think ownership is at issue here. A resourceful criminal uses the materials at hand. Or what he can find in his best friend's office." The tin of shoe polish he kept in his bottom desk drawer was missing, just as he'd suspected. "I don't get it," Wilson said. "Cuddy steals your cane, sets up a trip wire in your doorway, freezes you out of your own apartment, and you turn the other cheek like you're the second coming of Christ."

"You forgot making me walk up and down three flights of stairs," House interjected, grunting slightly as he pressed down on the three-hole punch. The lever stuck halfway, and he struggled to pull the papers free. "Here," he said, pushing it towards Wilson. "Make yourself useful."

Wilson inspected the hole punch and saw that the cylinders had only perforated the first few sheets, jamming the rest in the slot. He toggled the lever and pulled gently at the stuck sheets until the cylinders popped loose again, and then halved the stack and punched the papers neatly. "Why the sudden return to grade school? Has she committed some new indignity upon you? I hope it was painful." He punched the other half of the stack and looked around for a binder.

"Keep punching," House ordered. "I want a big pile of confetti." He fished around in his desk drawer, crowing triumphantly when he found a tube of Super-Glue. "And she hasn't done anything. That would defeat the purpose. When you're done with that, go get me the dishwashing liquid from the lounge."

"You have a purpose?" Wilson asked doubtfully. "I didn't realize your madness required any method. And get it yourself." He pushed the hole punch back towards House. "Don't make me part of your suicide squad," he said, though dish soap in the toilet tank was one of his personal favourites.

"You're afraid of Cuddy."

"Yes. Because I'm sane. Rational adults don't poke a stick at a hornet's nest." And they made sure they were far away when their idiot friends did. Unfortunately, Cuddy's flight path always took her through his office.

"Please," House scoffed. "Cuddy loves this. It makes her feel like one of the guys. The way she was before the operation."

"The steam pouring from her ears was definitely a sign of happiness." He stared suspiciously at House. "This is some kind of bizarre mating ritual, isn't it? She makes you miserable, you make her miserable, and then you join your misery together in unholy union."

"If you equate pranks with courtship, why haven't you made me an honest man yet?" House asked, fishing in his backpack for a bottle of clear nail polish. "My mother warned me about men like you."

That was just wrong. House's mother adored him. "Are you making yourself pretty for her?"

"Bite your tongue," House retorted. "I don't believe in inter-species mating."

"So now she's a non-human transsexual?" Wilson considered the growing list of possible pranks with dismay. "I know it's just a drop in the bucket for you, but Cuddy's threatening to give us both extra clinic hours the next time Mad Prankster strikes. As if being your friend isn't punishment enough," he muttered.

"I could care less, but not by much," House said. "So since you're going to pay the price, anyway, you may as well have some fun." He pushed the hole punch back towards Wilson. "Go big, or go home."

"What are you going to do with the confetti?" Wilson asked, against his better judgment.

"I thought I'd put it in her umbrella."

"It's not raining," Wilson pointed out. "I didn't think you believed in delayed gratification." House had trouble waiting for Pop Tarts to toast. Wilson, on the other hand, believed that payback was best when least expected. "We could hide it in that desktop fan she has."

"Are you expecting a heat wave in February, or is Cuddy in menopause and I hadn't noticed?" As if that could ever happen. "It'll rain long before she turns on the fan."

"Not if we reset and lock the temperature controls in her office." It was worth the extra clinic hours to see the look of genuine admiration on House's face.

"Overheated office equals bare skin in February," House mused. "Spring break for the twins! You're wasting your talents in oncology."

"Right. Because plotting practical jokes is so much more worthwhile than treating cancer." But Wilson filed the comment away in the small compartment of his memory designated for the compliments -- most of them backhanded -- that House had paid him over the years.

"You said it not me." He tossed the nail polish to Wilson. "Cuddy has a meeting in the board room in fifteen minutes. We'll strike at 13:40 exactly. You can use your vast experience with nail polish to cover the tips of all her pens and pencils, while I glue the handset to her phone. Diversionary tactics before the main strike. I'll take care of the temperature controls. Blue owes me."

"So this is payback."

"This is re-establishing order in the universe," House corrected.

But House's motives were never that simple. Wilson thought about stethoscopes on door handles and sabotaged chairs, and wondered if this was House's way of letting Cuddy know that everything was back to what passed as normal between them.

He pocketed the nail polish and synchronized watches with House. Maybe he'd stop off at the lounge after all. If he was going to take a fall for House, bubbles might cushion the landing.