I was sitting in a soundproof studio in Los Angeles a few years back, recording an episode for a popular retrospective podcast.

The host and I had been chatting for almost an hour about my time playing Trapper John on MAS*H.

We had covered all the standard topics.

The blistering heat of the Malibu mountains, the long hours, and the incredible writing that made the show a classic.

But then, he leaned across the table, checked his notes, and asked me a completely unexpected question.

He asked if it was true that the cast used to relentlessly torture Larry Linville behind the scenes.

Hearing that name instantly brought a massive smile to my face.

Larry played the character of Major Frank Burns, the most universally despised, irritating, and pompous surgeon in the 4077th.

But in real life, Larry was the absolute sweetest, most gentle human being you could ever hope to meet.

Because he was so fundamentally decent, he was the perfect target for our practical jokes.

Alan Alda and I practically made it our part-time job to mess with him.

That podcast question immediately triggered a memory of a very specific afternoon during the second season.

We were filming inside “The Swamp,” the canvas tent our characters shared.

The script called for Frank to have a total meltdown.

He was supposed to be furiously packing up his gear, threatening to leave the camp and report us to a general.

The physical comedy of the scene required Larry to grab his massive Army canvas duffel bag, dramatically swing it over his shoulder, and storm out of the tent in a huff.

We had rehearsed it a couple of times with an empty bag, and Larry had the timing perfectly dialed in.

The director called for a short break to adjust the massive studio lights.

Alan and I looked at the empty duffel bag resting on the dirt floor, and we shared a very devious, unspoken look.

While Larry was outside getting a sip of water, we quickly went to work.

We knew the cameras were about to roll, and the tension in the room was high.

The director yelled for everyone to take their marks.

Larry stepped back into the tent, perfectly adopting his signature Frank Burns scowl.

And that’s when it happened.

The director yelled action, and Larry immediately launched into his furious tirade.

He was absolutely brilliant, delivering his lines with that trademark high-pitched indignation that made Frank Burns so hilariously pathetic.

Alan and I were lying on our respective cots, pretending to ignore him, which only made his character even angrier.

He reached the climax of his speech, delivering a final, stinging insult to both of us.

Then, he bent down, grabbed the thick canvas strap of his duffel bag, and violently yanked it upward to swing it over his shoulder.

But the bag didn’t move a single inch.

Larry’s arm stretched straight out, practically popping out of its socket, and his momentum caused him to stumble awkwardly backward.

He let out a completely unscripted, highly undignified squeak.

During the five-minute lighting break, Alan and I had snuck outside and filled the bottom of his duffel bag with a massive pile of heavy rocks from the Malibu set.

We had also thrown in a couple of solid iron stage weights we borrowed from the grip department just to make sure.

That bag must have weighed easily over a hundred pounds.

But the absolute best part of the entire moment was Larry’s dedication as an actor.

Instead of breaking character and asking why his bag was suddenly glued to the floor, he tried to play it off.

He gritted his teeth, let out a strained groan, and attempted to physically drag the monstrously heavy bag across the dirt floor.

He looked like a man trying to pull a parked tractor with his bare hands.

His face turned a bright, dangerous shade of crimson.

Alan couldn’t hold it in for another second.

He completely lost it, rolling over on his cot and burying his face in his blanket to muffle his explosive laughter.

I immediately broke character too, sitting up and laughing so hard that my ribs actually ached.

Our director, who had been watching on the monitor, let out a roaring laugh that echoed through the soundstage.

He was laughing so uncontrollably that he couldn’t even manage to yell cut.

The camera operator, trying desperately to keep the shot focused, started shaking from his own suppressed giggles.

You could visibly see the heavy studio camera bouncing up and down on its pedestal.

Larry finally dropped the strap, stood up straight, and looked at me and Alan.

His Frank Burns scowl slowly melted away, and he let out his real-life, booming, warm laugh.

He called us a few colorful names that I cannot repeat on a podcast, and then walked over to inspect the bag.

When he saw the pile of boulders we had shoved inside, he had to sit down on his cot because he was laughing too hard to stand.

It completely derailed the production for the next half hour.

Multiple retakes absolutely failed because everyone in the room was still recovering.

Every time the director called action, Larry would approach the bag, and before he even touched it, a collective wave of snickering would ripple through the crew.

We eventually had to take all the rocks out just to get through the scene, but the damage was already done.

That childish prank became a legendary piece of inside humor on the set.

From that day forward, whenever the script required a character to pick up a box or a piece of medical equipment, the actors would suspiciously kick it first.

We were all paranoid that someone had secretly filled our props with lead weights.

It became a running joke that lasted for years.

Whenever I look back on my time in the Swamp, I don’t just think about the dramatic medical scenes.

I think about the sound of a camera crew completely shaking with laughter inside a hot canvas tent.

When you are working fourteen-hour days in the sweltering California heat, you have to find a way to let off steam.

Humor was our survival mechanism.

Having a guy like Larry, who was willing to be the butt of the joke and laugh louder than anyone else, was a rare gift.

It reminds me that the best moments in any job are rarely the ones written in the official script.

Have you ever pulled a harmless prank on a coworker that ended up becoming a legendary story in your workplace?