I've been running a campaign with a group of friends for five years now. I've put them through horrors and evils that have left them literally ready to pee their pants. And.... I'm running low on ideas.
The campaign is a semi-modern game featuring the monsters of the Cthulhu Mythos, along with many beasties of my own design. If anyone can give me ideas for a new, horrible monsters or terrifying-or just plain disturbing-situations, I'd really appreciate the help.
Five years, guys. Do you want killing that campaign on your conscience?
Do a "Phantoms" scenario. I.e. the party walks into a walled fort or town or some such to find it completely deserted. No signs of struggle or even of any great movement. In fact, it seems also as if everyone just vanished in the middle of eating. Food is half eaten and rotting on the tables. The players find laundry dried but unfolded lying out. Things like that. It turns out the whole down was eaten by a semi-sentient psionic far-realm ooze, or perhaps a swarm of tiny aberrations or the like. This entity has absorbed the knowledge of the people it has consumed and has gained a sort of nightmare conglomerate personality. It thinks its some sort of infernal or perhaps even good god and begins to terrorize the players with nightmarish shape-shifting constructs in order to cow new worshipers... or try and gain more food.
I only used the first part (empty living area) and the like, but in creeped the living piss out of my players.
I love me some Lovecraft
Lets see, the pc's stumble upon a remote town in the forest. All of the npc's are both curious and frightened of the pc's upon entering the town, come to find out some otherworldly creatures(fell taints) have been keeping the townsfolk trapped in the village. Anytime they go to leave they are attacked, any who return are catatonic for about a day or so and after have an immense fear of going outside the walls. Turns out the fell taints are minions of a beholder that recently began living in the caverns beneath the town, the beholder can see through the eyes of any whom the fell taints have affected. He enjoys watching the town as a twisted experiment and plans on taking the town as his own once they have fallen apart due to hunger/stress/insanity. When the beholder is looking through the eyes of a person, their eyes dialate like a snakes slitted pupils which may tip off the pcs .Perhaps by sneaking/tracking you can see fell taints comming into/out of the caverns. When the beholder dies all those who were affected go completely insane and begin massacring the town from the inside out, the pcs final job is to protect the survivors (if you want there to be any)
You could also do something along the lines of Dagon
While sailing the Pcs see a landmass that is simply incomprehensible, they feel helplessly drawn to it. Once they set foot on the landmass they have to make a will check vs a mental break down howeer often you choose (the mental break down has whatever reprecussions you desire- saving throw ends- cumulative -1 to will throws until back aboard the ship)
The island should be filled with something like shaugin but more abberant maybe with an attack that aims at will. The Pcs continued to be drawn to the center of the island. There is a large black (pit with water spilling into it) or (pool with the monster lurking in it) either way the Pcs are confronted by something otherwolrdly (maybe de-level dagon?) after picking up a wine bottle sized black obliesk, if the Pc's drop or break the obleisk the island quakes as it begins to sink. (you want the obliesk to break somehow)
The idea should not be to fight it but to run.
The creature chases them, attempting to knock them prone. They should beable to out run the creature barely. When they board their ship they might find the crew dead, displayed like some morbid alien art, or possibly a battle with the creature that was chasing them.
Maybe this island comes and goes periodically, or you could somehow tie it to my other adventure idea, there could be an island tribe that is in fear of/worships the creature you thwarted/slayed and you now get praise/hunted for it
Silly question but have you mined the old Chaosium supplements and campaigns for ideas? How about Pagan Publishing's stuff? Or even old issues of The Unspeakable oath?
What is the time setting of your camaign?
An Imprisoned with the Pharohs type adventure might be fun.
You mentioned that it is semi-modern as in our world or Contemporary Fantasy modern. If so that could have a very big effect on mood, another question is tech level.
If it is a Fantasy Modern have them only able to take 5 with out the extendend and to really throw them for a loop interrupt thier 5 every once in a while. THis will force them to rely on thier at wills and encounters.
As for a scenerio why not try a Silent hill enironment where one moment the place is all normal and then another it dragged into the far realm with the players along for the ride.
Sparkchaser, good question. A little background is in order!
The idea is, as I said, semi-modern. 1940's, to be precise. The party was part of a group of soldiers sent to secure Berlin. Upon arriving in the Hitler's base, however, they find enemy soldiers arrayed everywhere, dead, like morbid art. The Chancellor himself is lying in the center of a ritual circle, and it appears something has broken out from inside his ribcage (think Alien...the little buggerdy chest-bursters), surrounder by the words "ph'nglui mglw'nafh Cthulhu R'lyeh" within the circle and names of various Great Old Ones outside it.
Shortly after, the Great Old Ones themselves crash to Earth, along with their servants, including the wonderful critters of your nightmares native to D&D. The PC's now contend with monsters, maniacs, and the mutated last remnants of humanity. Respect your Elder Gods!
Keep up the ideas, guys. I just primed my players for nightmares with a bathouse that had become a slaughterhouse. Our cleric refused to go home in the dark. Brings a tear to my eye!
Ah! So the monsters of the mythos are no longer lying in the deep dark corners of the world and mind. Interesting.
Let me ponder on this a bit.
Maybe add an action/spy thriller/technohorror to the mix. The Cthulloids are trying to take over the German scientists in order to build the German nuclear bomb or to use V2 rockets to spread Cthulloid spawn around the planet. Heroes of Telemark or Dambusters might help out.
Also with the end of the war the Cold war might start - so the Allies and the Russians will probably try and grab as much Mythos as they can in preparation for the next war. The players might aid one side or the other or try to intervene to stop the insanity. Who's going to tell Stalin he shouldn't be trying to tame the Deep Ones? Not me...
Hehe I like the idea of "open conflict" with the elder things btw, I guess I'll steal that for a future campaign :p
Back on topic what if you add some supernatural creature that appears friendly to the characters? One that actually helps them, but maybe is even creepier than the other monsters, with some weird love for living preys for example. Or it can provide some complex moral choices, "Will I accept the help of this creature?" "Can I trust it?"
As a bonus it could even have good intentions for real (as much as any elder thing or chtuloid monster can have good intentions ofc).
I've collected plenty of news items suitable for modern CoC games at the Arcana Wiki (browse through the various years in the timeline to see more of them). Many were taken from the discussions of the Delta Green Mailing List - Delta Green is a modern-day campaign framework for Call of Cthulhu which you really need to get. Right now.
I'm not kidding about this, mind you.
The Random Adventure Seeds Generator might also be useful for this purpose - it helps you "bring together dissociated pieces of knowledge", as H.P. Lovecraft himself put it. Some examples are provided.
I was going to suggest Delta Green. Sadly I cannot find a reasonably priced copy of it. One neat thing about the background of the Delta Green unit was how they reduced the power and influence of the Deep ones (cast summon Deep one spell and shoot anything that showed up and depth charge any suspected Deep one city).
Back to the OP's campaign: can i assume that since your PCs were in berlin that Germany already fell and summoning of the eldritch horrors was a last ditch effort of the Germans to win the war?
Now that all these beasties are running around, I would imagine that less than scrupulous nations would be trying to summon and bind these creatures to do their bidding. Oh, and evil cultists too.
What allies do the players have? Is Rome an asset or a liability?
Will the search for tools to summon and control these beings lead interested parties to long lost temples with their own dark secrets?
Did the Mi-go save Hitler's brain?
Are the Deep Ones establishing new colonies off the coast of New York and Boston and Seattle?
London newspapers are reporting an increase in missing persons reports and recently several limbs were found in the sewers. Has the Beast of London returned?
Nothing scares the crap out of my players more than the following 2 words.....
"Underwater level" 
Works well in a Lovecraftian mythos world too. I've been planning a adventure setting that I'll probably never use, a city inhabited by people, machines and animals which are being controled on the inside by a race of Sentient technologically advanced Jellyfish. They evolved in our own sea in a manner not unlike the hermit crab, only the many limbs of the Jelly fish gave them a much greater ability to use tools and therefore benefit from increased brain power. Their fragile forms mean they benefit greatly from metal junk disguarded into earths ocean (Ships sunk during ww2 for example).
Oh, you have no idea. "Underwater level"? Bad. "Underwater level with Dagon"? Worse.
Thanks for all this, guys! It's helping a ton!