A/N: This was written for Lucas Wahl Appreciation Week, created by Tumblr user truthisademurelady. Check out Archive of Our Own for the rest of the collection! Fics are being posted yesterday through April 6th.

Lucas' favorite holiday as a child had never been Christmas. He'd enjoyed presents, Santa Claus, and breaks from school as much as the next kid, but December 25th wasn't the best of the best. Halloween—a free day to dress like any comic character he wanted without fear of judgement—was near the top, but not quite there. Not Thanksgiving, 4th of July, Easter, St. Patrick's Day, the Ides of March...definitely not Valentine's thanks to the number of times he'd been brutally shot down by girls in his youth. The one holiday, that stood tall above all the rest was: April Fool's Day.

Not a year had gone by since grade school that Lucas hadn't diabolically plotted out pranks to play on his parents, friends, teachers (a few detentions to show for it), and later college roommates. From swapping condiment shakers to the infamous short-sheeting trick, Lucas and perfected them all. No one was safe.

No one, that was, until he began working under Doctor Morgan. To say that Lucas had been too intimidated that first year to try any pranks on his boss would be the complete and utter truth. It'd only bruised his ego slightly to put aside his April weapons, but the livelihood of his job was a tad higher of a priority. Last year hadn't fared much better. Lucas had been on the verge of gluing his boss' office phone to the receiver, but had ultimately decided it too risky.

This April, however, would be different. Doctor Morgan had warmed up in recent months. He had actually come out for drinks with Lucas and the rest of their co-workers several times, and no longer skated through every conversation like it were a chore to reveal an ounce of personal information. Okay maybe he still did the latter most of the time, but there was definite progress. Most in importantly, Lucas was fairly confident that his shenanigans would not get him fired. Sort of confident. At least seventy-five percent.

Mostly sure would have to be enough because Lucas had been sitting on his prank ideas for three years and he was not going to last the wait of another one. The only question was where to begin.

Lucas walked into the morgue on the first of April with an arsenal under his belt. Actually, most of his supplies were in his backpack, but that didn't sound as cool for an internal monologue. It had been too difficult to decide on just one prank to subject upon his boss, so Lucas had brought along a variety. Some of his best and brightest tricks from over the years—oldies-but-goodies so to speak—would be accompanied by a couple newbies he was trying out for the first time. After three years of confining his crafty spirit, Lucas could hardly be expected to just settle for lame snakes in a can, or something of the sort. Today was going to be good. Assuming Lucas was still employed by the end of it—seriously hoping.

Doctor Morgan wasn't yet in his office when Lucas arrived, as per his usually routine. Lucas had actually given himself an extra fifteen minutes to be safe, but his caution wasn't necessary. The first item was in place right on schedule.

Lucas sat at his desk and waited, pretending to be in deep concentration working on a report. Every so often he twitched an eye over to the doors, keen for the arrival of one Assistant Chief Medical Examiner. The minutes ticked by. He jerked his head twice at the sound of the doors opening, but both times it was the wrong person.

Then finally… "Good morning, Lucas."

"Oh! Yeah, uh, good morning. Totally." Lucas had been so distracted with waiting, he'd let his attention drift away from the very thing he was waiting for. And now Doctor Morgan was looking at him like he'd grown a second head over night. Play it cool. "Sorry, I was just…working. On this report." Lucas tapped the file in front of him, realizing just a bit late that he'd neglected to take a pen out. "So I didn't notice you come in. Yep."

Lucas hoped dearly that he didn't sound as transparent to Doctor Morgan as he did to himself.

"I see." Doctor Morgan stared at Lucas a moment longer before shaking his head and continuing the walk towards his office.

Lucky for Lucas, he tended to act odd on a regular basis, so his boss might not look too closely into the nervous behavior. At the very least there wouldn't be time before Doctor Morgan stumbled across prank number one. Lucas leaned forward in his chair, eagerly listening for indication that the fake spider on his boss' desk had been discovered. A yelp. Shout. Gasp. Something.

Instead, he heard Doctor Morgan calmly question, "What is this?"

Lucas held his breath.

"Lucas? Did you put this in here?

Prank number one and not only had he struck out on the shock factor, but he'd probably be dead before he could try again.

"Lucas?" Doctor Morgan came out of his office, spider in hand.

"Oh, thaaat." Lucas dragged out the second word, aiming to give himself time to think of an explanation. He could've recited the entire alphabet and come up with just as much nothing.

"It's remarkably accurate for a toy depiction. Theraphosa blondi. Or, more commonly, a Goliath birdeater. Second largest spiders in the world. They don't actually consume birds, but have been known to feed on bats and even venomous snakes." Doctor Morgan placed the faux arachnid on top of Lucas' paperwork. "Very interesting creatures. Did you know that on average the females lives five times longer than the males?"

"Nope, but I do now!" Lucas replied cheerfully. His boss was so caught up in giving the encyclopedia entry on the spider, he hadn't thought to ask why Lucas had put it on his desk. Mission April Fools was still on.

Lucas let Doctor Morgan ramble on for another minute about the eating and mating habits of Goliath birdeaters, nodding when appropriate and occasionally giving an informed hmm. He was plenty used to the meandering lectures, so feigning interest wasn't hard.

When Doctor Morgan finally returned to his office, Lucas commenced stage two. After double-checking that his boss wasn't watching him through the glass, Lucas took a jar out of his backpack. Inside was the most realistic-looking human eyeball he could find, encased in green gelatin. Mixing the packet of Jell-O had been the most cooking Lucas had done all week. Under close inspection Doctor Morgan would easily identify the eye as synthetic, but Lucas was crossing his fingers that the gelatin would obstruct sight just long enough.

Lucas checked the logs for the latest body delivery, and casually made his way to the correct freezer. He kept the jar tucked close against his body, on the side not facing Doctor Morgan's office. That left it completely visible to anyone entering the morgue but Lucas planned to act quickly. The freezer drawer above the body was empty. Perfect. Lucas put the jar on the shelf and closed the freezer with a swoosh.

It suddenly occured to Lucas that if anyone had to get into that particular freezer before Doctor Morgan started the autopsy, Lucas would have a lot of questions to answer. Even more than the spider. Which reminded him...he should probably put that away before he forgot about it and scared himself. Lucas had a healthy discomfort of arachnids that he had considered before using a fake tarantula as a prank, but it had seemed worth the risk at the time. Lucas hurried across the morgue and shoved the spider into the bottom of his backpack.

While Lucas was situating that, Doctor Morgan emerged in his white lab coat.

"I assume we already have a body to get started on?"

"Yeah, it was brought in late last night. Male in his fifties—over in that one." Lucas pointed to the freezer that now housed the deceased, and his own special addition.

Doctor Morgan opened it.

"Is that...gelatin?"

Lucas strode over, employing his best acting voice. "Oh, whoops. I forgot that was in there. I've been doing some experiments lately. Y'know human eyes, tongues. I figured it would be better to store in there than in the break room fridge." He watched his boss' face, gauging for a reaction. Or, really, for the reaction he was hoping for.

But Doctor Morgan was nodding, almost in approval. "That's a good way to gain perspective, and to recognize certain injuries in the future. I wouldn't put it in gelatin, though." Doctor Morgan leaned closer to the jar, squinting. "This eye isn't real." He turned to Lucas.

"It's...a...medical replica. Let's you have all the fun of dissecting without being arrested by the FBI for buying human body parts."

"Ah. Good idea, Lucas." Doctor Morgan switched his focus to the body underneath. "And who do we have here...strangulation, I'd say."

And that's about how well Lucas' day went. Every time he tried to set up a prank, Doctor Morgan was either unfazed, uninterested, or unconcerned. Even his toothpaste in Oreos idea—for which he had sacrificed half a pack of cookies—fell flat. His boss refused to try them. (Lucas probably should have seen that one coming with how much of a food snob he was.)

By four o'clock Lucas had tried every single trick he'd brought. He scraped around the bottom of his backpack, hoping for just one more that he had missed. Something he'd forgotten. He had done so much preparation for today there was no way he wanted to give up now, but he was fresh out of ideas. If he had known pranking his boss was going to be this impossible, he would have started three years ago for practice.

Lucas made a trip upstairs to clear his mind, and replenish his supply of caffeine. There had to be one more prank he could try, He'd even settle for switching sugar and salt shakers at this point, but Doctor Morgan didn't use the break room. Today was what Lucas would define as a lost cause. He stopped off the elevator, coffee in hand, and pride in the other. He had failed at properly commemorating his favorite holiday.

On the trek back to his desk he decided to just start planning for next year. It might take that long to invent a prank that would be successful. Fool proof.

However when he reached his desk, his desk...wasn't there. Well the actual desk was there, but everything on it—computer, keyboard, files, pens, pencils, paper clips—had vanished. In their place were items Lucas had only seen in old movies and antique shops. A typewriter sat where his computer had been, paper loaded and ready to go. All the modern writing utensils were now old fountain pens, sitting beside a stack of worn, brown parchment paper. His original materials were no where to be seen. Lucas sputtered, unable to do little more than stare. He'd been gone for what, five minutes? Ten? How does someone replace an entire desktop in ten minutes? And who—

"Hello, Lucas. I see you're back." Doctor Morgan was standing beside one of the autopsy tables, casually leafing through his notes. He wasn't making any attempt to shield the triumphant smile on his face.

"You...how?" Lucas whipped his head back and forth between his transformed workspace and Doctor Morgan. Of all people to prank him on April Fools' Day, Lucas would have ranked his boss last.

"I believe it's customary on April first to play tricks on the people around you. I'm certainly not admitting to anything, but that's what this appears to be." Doctor Morgan looked incredibly smug, and sounded even more so, but Lucas had to hand it to him. This was good.

Perhaps Lucas' failed pranks throughout the day hadn't been as coincidental as he'd thought.

Doctor Morgan put his notes aside, strolled up next to Lucas and patted him on the shoulder.

"Better luck next year."

A/N: I feel like Lucas would be a pretty dedicated April Fools' Day fan, and able to hold his own as far as pranking. Too bad henry has lived with Abe most of his life.