Here's another silly story - same author, same link:
Cthulhu always has the best, doesn't it? Something about normal schlubs in completely over their heads and just flailing. Here's my favorite from an older campaign, which you may have seen if you were on yog-sothoth.com back when I was more active there. (I seem to recall a cjbowser on y-s.c, am I remembering correctly?)
SPOILERS, don't read if you're a player.
I'm running a group of Cthulhu newbies through the classic "Shadows of Yog-Sothoth" campaign. One of the main villains in the campaign is an evil sorcerer of immense power. He has a pair of "Gate Boxes," innocuous-looking boxes that contain a magical portal that lets you crawl through one and come out the other, no matter how far apart they are. (Using this causes a Sanity loss, typical for magic items in CoC).
The sorcerer has a gate box in the basement of his hideout in Boston, with the other one in upstate New York to allow for a getaway. The PCs (an author, a private eye, a professor, a grad student) raid the hideout in the wee hours, barely escape with their lives, burning the lair to the ground, but managing to grab the Gate Box on the way out as an afterthought.
Then they promptly put it in their safe house and forget about it for a week.
So what would the evil sorcerer do? Sending minions through it into the PCs' house, guns-a-blazing, is one thought. But maybe he didn't get to be long-lived by frontal assaults. I decide that he will take a ship to the next scene of cult shenanigans in Scotland, and send the box on a different ship, guarded by minions (can't be too careful!).
By the time the PCs remember the box, the ship with the other box is halfway across the Atlantic. The PCs are cagey. They poke around the bottom of the box with a cane. The cane goes through with no resistance (coming out the bottom of the other box, but they don't know that). They throw a penny into the box. They spit through the box. Finally one gets brave and sticks his hand through the box, then his head. Then three of them crawl through the box and out the other side into an empty state room on a ship (losing Sanity).
The one who stayed behind, the author, was heavily wounded from the previous escape and didn't want to risk danger. So he gets out a shotgun and watches the box.
On the ship, they poke around, find some clues. Then they hear someone coming! They all hide in a wardrobe and close the doors. Two cultists enter the room! They look around -- something is amiss but they can't put their finger on it. The professor says "I get out my pistol and cock it." "Okay," I say, and give the cultists a Listen check to hear the sound of the hammer being pulled back (players swear gratuitously). The NPCs pass the check, draw pistols, and start walking toward the wardrobe.
The PCs fly out of the wardrobe and fill the air with lead. One of the cultists has high DEX and fires first at ... rolling target randomly ... the professor. 03, critical, impales for double damage. I roll something ridiculous, like 18. The prof's head is blown off. (PCs lose sanity.) The other PCs quickly gun down the cultists. They try to listen at the door but can't hear anything -- their ears are ringing! They decide to hightail it. But they don't want to leave a friend's body to be discovered! How to get rid of an inconvenient body? The portholes are too small. Wait! We have a magic box here!
They grab the prof's body and feed it through the Gate Box (Sanity loss for grisly handling of a friend's corpse). Meanwhile, back in Boston, the author, bandaged and cradling a shotgun, having no idea what's happening, sees his friend's headless corpse suddenly plop out of the box like a sack of potatoes. (Sanity loss.)
He gets up, runs to the liquor cabinet, and starts making molotov cocktails.
The other PCs, still on the ship, start barricading the door to the state room with furniture. Pursers are beating on the door, asking if everything is okay. The PCs ransack the rest of the room, looking for clues, then decide "screw it" and dive through the box (Sanity loss).
Seeing his friends start to come through the box, the author starts lighting Molotovs. The PCs clamber out of the box onto the floor. The professor's body is bleeding all over a beautiful Persian rug.
As soon as the last PC clears the box, the author flings a lit Molotov into it, followed shortly by two others. They nail shut the lid of the box and wonder what to do.
Problem #1: the dead professor is a high-society type whose murder will have to be explained.
Problem #2: even if they ditch the body, there is now a large, spreading bloodstain on the rug.
They start flipping out. How will they explain the death? Will they just leave the body to be discovered? What do they tell the inevitable police detectives, who are possibly receiving payola from the wealthy cult? And what to do about the rug?
One of the PCs tries dumping an inkwell on the rug to hide the bloodstain and just makes a huge mess. Now there's an obvious attempt at a cover-up.
"@#$!," say the players. They decide that a mysterious disappearance is better than a body.
So they stuff the body back through the Gate Box (another sanity loss for mishandling a close friend's corpse). They roll the bloody rug up and stuff that back through the Gate Box.
Then the author goes out to the woodpile, grabs an axe, and chops the Gate Box into splinters while swearing at it in most ungentlemanly terms.
Unfortunately, that wasn't the end of their problems. Starting a fire on the inside of a barricaded state room on a ship? I decided that there was a chance that this could spread and eventually damage the ship enough to sink it. I rolled d% and beat my estimated chance. The ship sank. Hundreds of people died. A passing ship attempted a rescue but couldn't get there in time to save everyone. But there was a photographer on board who managed to take some pictures (supplied by a helpful forum member).
So I got to make up a mock newspaper story for the PCs at the beginning of the next session. OCEAN LINER SINKS, HUNDREDS DIE. Surviving crew reports blaze started in mysteriously barricaded stateroom....
(PCs take huge sanity loss for inadvertent mass manslaughter.)